


Dancer

by naggeluide



Category: Avatar: The Last Airbender
Genre: Accidental eyeball symbolism, Alternate Universe - Cyberpunk, Alternate Universe - Mutants, Alternate Universe - Post-Apocalypse, Gen, Katara's hair does a Claudia, Language Barrier, Multilingualism, One does not simply walk into Baikonur, POV Sokka (Avatar), Science Fiction Elements, Sliding scale of humanity, This is not a nice world, Toph Beifong and Zuko are Siblings, Toph and Zuko are potty-mouths, Zuko's hair journey in reverse, and finally uses their cultural anthrophology degree, blatantly incorrect physics, by which I mean the science is clearly fiction, local scientist gives lecture on atmospheric phenomena, quotes stolen from Portal this time, sorry any real tags are definitely spoilers, very hand-wavey on the bioengineering
Language: English
Status: In-Progress
Published: 2020-03-31
Updated: 2020-09-25
Packaged: 2021-02-28 18:34:43
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 14
Words: 47,147
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23391811
Author URL: https://archiveofourown.org/users/naggeluide/pseuds/naggeluide
Summary: So, Sokka might have panicked and stolen a Fire Nations warship. While dragging his sister along.Aaaand he might have also kidnapped its owner too by accident.---That cyberpunk-ish AU where Sokka and Katara join Zuko's hunt for the Avatar, and what they find is more than any of them bargained for.
Relationships: Azula & Zuko (Avatar), Iroh & Zuko (Avatar), Katara & Sokka (Avatar), Katara/Yue (Avatar), Sokka & Zuko (Avatar), Sokka/Zuko (Avatar), Toph Beifong & Zuko
Comments: 231
Kudos: 363
Collections: Legends of Kolor (A collection of ATLA and LOK fics written by POC)





	1. When the call came down the line

As rumor had it, Ozai's hellspawn was indeed a flaming dick.

Amazing, the things that Sokka's hyper-intelligent mutant brain spat out sometimes. True, nonetheless.

Because after all, the Fire Prince _had_ crash-landed his ship in a smoking skid of radioactive garbage that went right through the village's two-meter-thick shield dome. Said dome hadn't been meant to halt physical objects so much as to absorb ambient radiation, so Sokka could almost forgive the demon-child that one, but then the guy had emerged from the semi-wreckage with radiation _thrumming_ through his veins and proceeded to wreck shop.

Sokka's shop, in particular, and that shop was Sokka's _baby_ and he wasn't going to let some so-called fire mutant with physical — and who knows — probably mental mods up the wazoo get away with that shit.

Thumbing a button, Sokka targeted and launched a heat-seeking titanium spear and then dashed in to close the distance with his shock glove. The prince raised a leg, smashed the spear into shards with a kick, and then attempted to do the same to Sokka without even bringing the limb down to rest.

Owww. Yup, definitely some strength and speed mods there, no way was that ferocity natural. Without conservation of momentum on his side, Sokka might be in the same pathetically twitching pile as the spear remnants right now. Sokka rolled to his feet, for once wishing that his own genetic irregularities had more physical advantages, and blinked back the double-vision.

Close up, his mind had locked on a few key features of the Fire Prince's appearance for quick analysis. Typical clothing for Fire Lord Ozai's elite super-soldiers, consisting of black and blood-red kevlar-synth blend highlighted in gold, obscured any of the more obvious physical mods that had been made to the elegantly muscled frame. What was really worrying, though, was the Tracker's eye. Or rather, where the trademark red-tinged synthetic organ should have been.

Instead, an angry red swath of scorched flesh covered most of the left side of the man's face — perhaps an extraction gone wrong, but it was fairly easy to sub out the optic nerve these days so it was more likely an _installation_ gone wrong. Which didn't add up, because the gold iris behind the scorched slit was _clouded_ , but there was no way it should be bio. If the guy's body had rejected the vision mod, there'd be no reason to stick his natural eyeball back in for vanity purposes, and if the burn was just an injury — an old one, too, by the looks of it — why would he choose to keep the dead organ?

Sokka would have to critique his opponent's questionable accessorizing choices _after_ he finished getting that pile of walking plutonium out of the lab and then out of his village entirely. And anyway he wasn't about to look a gift horse in its blind eye.

He'd already accounted for his enemy's restricted field of vision, easy as breathing, and Sokka had just the weapon for that. If only he could _reach_ it…

Sokka dove under the nearby workstation's chemical hood, glad that he’d procrastinated on re-stocking the extra-strong acids, then rolled out the other side. Away from his objective, currently, but a distraction was in order, and boy did the Fire Prince deliver. His fist smashed through the table in a shower of glassware, and acids and bases combined with a hiss, sending obscuring clouds of mostly-harmless gasses into the air. The next instant, a lithe body twisted through the wreckage with the agility of an Olympic gymnast.

Hell, those were some crazy good mods. Sokka would be jealous except that his people didn't make a habit of mutilating children. Generations of living in an irradiated environment had done that just fine without the need for any external help.

Besides, Sokka thought as his fingers closed around the boomerang, who needed physical enhancements when they were smart enough to maximize use of the tools at hand? Such as this bad boy. 

Angles and velocities calculated, Sokka let the curved piece of sharpened metal fly.

"You missed," came the prince's smoke-and-brimstone voice, mouth curling in the beginnings of a smirk. _Well look at you_ , thought Sokka, _all grown up and trying to engage in conversation like an actual human being. Too bad I'm about to bash your CPU out._

"Did I, now," is what he chirped aloud, before Mr. Boomerang hit home.

On a normal person it would have been a kill shot. Sokka was immediately reminded that whatever it was he was fighting did not qualify as either normal or people.

The cross-eyed expression of concussed rage and humiliation was still just as funny on a cyborg face as it would have been on a fully human one. Sokka would be laughing, except that his usual buffer of fifteen steps ahead had now shrunk to five, and they were all rapid backpedals in the direction of his next potential weapon as the enraged mutant descended on him.

"Human," growled the demon-spawn, reeling in Sokka by the collar to stare him down with uncanny golden eyes.

This was all mildly terrifying, but Sokka was determined not to let the emotion take control. "What of it?" he retorted instead. Normally Sokka was as proud of his ninetieth percentile Zei Humanity Factor as he was of his ninety-ninth percentile IQ, but he hardly saw how it was relevant right now, especially given that his opponent was so obviously on the opposite end of the scale.

"Avatar. Where are they."

Well if it wasn't the flaming bastard's lucky day. Not many people would even recognize that English loanword that frequented pre-Apoc Cache-speak, much less be able to rattle off a definition. Maybe that explained why Sokka's _lab_ of all places was under attack from the elusive Tracker.

Still, Sokka was going to need more than two words and some gender-neutral pronouns to go on. Context was everything, and all that.

"Use your words," Sokka complained, stalling for time. He had no interest in helping the Fire Prince out even if he did know exactly what he was talking about, but backup should be coming soon, if his calculations of his sister's arrival time from her last known whereabouts were correct.

Right on schedule, Katara broke down the door, which was admittedly easy for her when she could just use her mutation to manipulate the ice around it into parting for her. And while Sokka would like the record to reflect that his little sister was an incurable show-off, he was really grateful for her flashy ice powers sometimes.

The Tracker's grip didn't slacken at all with Katara's entrance, but Sokka deemed the timing good enough to go for the tried-and-tested knee to the groin. Mod-enhanced reflexes enabled the Fire Prince to twist aside, dodging both that and Katara's icicle barrage, before he threw Sokka away to focus on the sibling with the water-manipulation mutation. Rude.

Katara didn't have a lot of combat moves but the ones she had served her well. Sokka knew she'd be liquefying a portion of the building next to wash the intruder out the door, and dashed to one of the electronics tables to prepare a zappy surprise for when that happened. Physics said that cyborgs and water don't mix, and Sokka was always one to bet on the laws of nature.

Out of the corner of his eye, Sokka could see Katara's wave was ready to release; he grabbed for a handful of old lithium batteries that he'd been about to recycle and prepared to throw.

The Tracker got there first, hurling a _stream of flame_ from his hands with an inhuman scream.

Steam erupted, filling the room and making it a perfect time for a sneak attack, but Sokka's brain was occupied for the moment, because _what the hell?_

Sure, hearsay said that Ozai's line had a fire mutation but Sokka had dismissed that out-of-hand because mutations _didn't work like that_. And he'd thought their grandiose titles like _Fire Lord_ and _Fire Prince_ were because their domain encompassed the remaining half of the Ring of Fire, known as the Fire Nations, not because they had… well, any actual fire powers. Much less ones that _lit up their veins_ with a hellish golden glow, to a distinctly unearthly effect.

If it weren't for Sokka's aversion to bioscience and the fact that he was focusing on survival right now, he'd have the guy laid out on a lab table in two seconds flat. Cyborgs traditionally mixed as poorly with fire as they did with water, and Sokka had never heard of a flame mod; for a fleeting second, he wondered if demons were indeed real and one had ascended from the pit.

The amount of fire and ice being flung around with impunity certainly resembled a lab-scale apocalypse, and its Nation-ending potential was not lost on Sokka. He knew Katara knew better than to allow the fight to get anywhere near the cryo-preservation units that held the Badu people’s viable seed and egg samples, but they hadn't exactly designed the lab with defense against an invasion in mind. Sokka's own survival was, however, currently in much higher jeopardy than his sister's future progeny; he felt justified for prioritizing that over some long-shot worst-case scenario.

Sokka ducked under a rapidly melting icefall and finally reached his magnum opus. As his fingers closed around the leather-wrapped handle, a space-black blade extended. The lonsdaleite edge could cut through metal and bone as easily as air, its vibration-damping structure rigid with cutting crystals the width of mere microns. Sokka felt it settle into his grasp in that same satisfying way that his spine re-aligned itself after a good stretch at the end of a long day of work… just as the worst-case scenario played out inexorably in front of his eyes.

Katara had finally gotten a perfect angle for a headshot and now her icicles were screaming down from above. The Tracker dropped to the floor, but not as an icy pincushion; he was just enough in advance of Katara's missiles to sweep his feet a full three-sixty in what looked like a crazy dance move. Flames roared high, melting the frozen projectiles and okay, the guy could shoot fire from his feet too now, overpowered much?

The unfairness of it all turned out to be the least of Sokka's worries. Because like an idiot, Sokka had forgotten about the damned coolant tubes running happily just under the ceiling, connecting the cryo-preservation units to the lab's powerful cooling unit.

Tubes filled with _highly flammable_ coolant.

The irony was just _crushing_ today.

So was the pressure wave following the explosion of the sum total of his gene pool's viable reproductive material and, for good measure, the freezer that contained it.

Sokka had been far enough away to escape the flying shrapnel, but he was just as unable to move as if he were pinned in place by sharp metal shards. The fight faded into the background, although there was no drop in its intensity, and Sokka knew the signs, but that didn't help him in the least. He could feel the pounding of his own heart start to fill his ears, and this was bad it was bad it was the worst.

Sokka blinked eyes weighed down by leaden lids, and felt a twitch of fingers that had suddenly become clumsy and slow. He registered a brief flash of flames diverted by an icy barrier, heard Katara's enraged shout, and hoped that the momentary clarity could beat back the fog. Action was what he needed right now, not thought, but he barely had a grasp on either. Sokka tried to focus on his sister, fighting on as if their own people’s little world hadn't just ended, and there wasn't even a point to it anymore, was there? Logically they should both just stop. On the bright side, at least Sokka's frontal lobe wasn't fully out of commission yet. Too bad he had the most stubborn sister in the world who'd come up against an opponent who looked like he would only quit when hell froze over.

It might have been seconds or minutes that had passed since the explosion; Sokka would never be able to tell, but then Katara was always slower on the uptake than he was. To tell the truth, though, so were most other people. Still, they were siblings, so when the full horror struck, Katara froze, too.

The difference was that when Katara froze, so did everything about her, thick ice forming from seemingly thin air. Twin screams tore the air apart; the cyborg, summoning an inferno from God-knew-where in an effort to escape the deep freeze, and Katara, as the anguish and disbelief washed over, through, and out of her.

An eerie silence fell, punctuated only by the odd remnants of flames guttering out. A small pane of ice cracked; Katara drew in a ragged breath.

Sokka wasn't breathing. Or if he was, he suddenly couldn't hear himself, because sounds were far away again, and his thoughts were sluggish, so far from their usual rapid-fire sparks.

When he could parse the signals coming from his body again, he realized he was shaking.

"Katara," he said, but his mouth didn't move so he tried again. "Katara."

She must have heard, because she turned away from the still-life scenery she'd created and he could see her mouth forming the words _oh, no_.

Sokka didn't know if it was because she recognized the state he was in or because the realization that it was all _gone_ had finally sunk in and she'd moved on to _what do we do now_ , and found a wall as impenetrable as the one Sokka's mind had come up against.

It was _over_ and the door was open on a dizzying divergence of possibilities. None of this should have ever even happened to his little Oceanarctic backwater that was doing its best to be forgotten by the rest of the world, and Sokka found the simplest of tasks slip away from him as his brain erected barriers in a last-ditch defense against the flood.

The last thing Sokka rightly remembered saying was, "I'm about to do something two fishhooks stupid, aren't I."

**Notes for the Chapter:**

> Very excited to finally introduce this work to you all! The rest of part one, chapters 2-8, will come out all in the same week once I'm done editing them, so probably mid-to-late April. I've decided to post this story one arc at a time, since I know I've stopped reading many fics once I no longer remember what happened in the last update.
> 
> I'd love to know what you think of this! Feel free to ask me anything [here](https://d-naggeluide.tumblr.com/) on Tumblr, although if it's something that will be answered later in the story you'll probably just get a cryptic answer. Also I'll eventually post there a badly-done sketch of Sokka and his (read: Asami's) shock glove from this chapter… once I'm allowed back in my office where I took it to scan and then forgot to do so…
> 
> Oh, and it was a deliberate choice not to use the name [Water] Tribe for Sokka and Katara's people, as there are more culturally appropriate terms. Full disclaimer regarding my efforts to fairly portray indigenous and minority peoples to come with the next chapters.


	2. Sometimes I get nervous

**Notes for the Chapter:**

> Welcome to update week!
> 
> Haven't finished writing the disclaimer yet, but rest assured that I am putting in the effort to not trivialize the cultures and experiences of real-life people groups reflected in this story.

So, Sokka might have panicked and stolen a Fire Nations warship. While dragging his sister along.

Aaaand he might have also kidnapped its owner too. By accident. 

The downside of his normally awesome mutation was that it, along with most of his other conscious cognitive processes, completely deserted him in the face of strong emotion. Not usually an issue for Sokka, since he was a rational guy by nature, and was also good at removing himself from situations where he was in danger of feeling too much. So he could count on the fingers of one hand how many times he'd lost it since he'd reached majority two years ago (and take _that_ , puberty, mind over matter for the win), but sue him if _failed-at-my-one-job-of-ensuring-the-genetic-survival-of-my-people_ didn't summon some strong emotions and an even stronger flight instinct. It was hardly _his_ fault that the Fire Prince's little dance trick had efficiently targeted all of his insecurities at once.

"Sokka." Katara's voice gradually broke through the mental whirlwind he found himself in. "Hey, Sokka, are you with me?"

Sokka looked around, finally registering his surroundings. "Yeah," he replied, but he wasn't one hundred percent sure. They were in a ship, but any moron could see that. What just any moron couldn't tell you, and what Sokka usually could, was what it ran on, how to get the thing started, and the operational trees of its five main systems.

He might still be panicking, just a little.

"Where's the Prince?" he asked, not liking that he didn't know the answer.

"I've got him restrained and sedated in the cargo. Don't worry about him right now."

"Yeah, I'll just go back to worrying about what the Council is going to do to me when they find out I let our last seed samples get destroyed by a glorified flamethrower. I bet that'll go over real well with Bato."

"Hey, Sokka, calm down a little. You know you're far more than just a DNA guardsman, right? The people need your intellect. This was… unfortunate, sure, but _you_ didn't destroy the seed bank. The _Fire Prince_ did. They'll get over it."

"Yeah, because now the Badu people are going to _die out_. Everyone will be super _over it_ when they're dead!"

Katara rolled her eyes. "It's not the end of the world, Sokka. That already happened," she tried to joke.

Sokka ignored her attempts at comfort and hit back as only an older brother could. "You're just saying that because you've been delaying getting knocked up from a test tube for over a year now."

Katara, unlike Sokka, had no 'flight' in her 'fight-or-flight' instinct. She was immediately ready to engage, tone heated. "I'm more than just my womb, just like you're more than your job, thank you very much. Is it so bad if I’m not sure I want what everyone else wants from me? If maybe I want to get away and be my own person if only for a day? Your subconscious certainly must have thought so or we wouldn't be here right now!"

Valid point, but thankfully Sokka wasn't rational again just yet. Commence shouting match. "We're not children any more, Katara! Even if we're the youngest on the island, you're fourteen and I'm fifteen! That's practically _middle-aged!_ We've got a duty to our people, I made a promise to Mom, I'm supposed to protect it, which means making sure we survive, and how is that supposed to happen now that our seed bank's gone?"

"There's a few women who can still freeze our eggs, and a dozen fertile men. Besides, our bank couldn't have been the only one, okay?" Katara was still capable of standard logic when she was emotional, but it was small comfort. "People went crazy stockpiling private strains when they realized almost every child was being born with a mutation and over half were born sterile! There's got to be something compatible with our gene pool out there. And now we've got a Tracker and his ship. There's still hope, Sokka. I know there is."

"Doesn't help much if one of the four fertile women in the Nation doesn't want to do her duty now, does it?" Sokka got in a personal barb in return for the one she'd aimed at him earlier. Katara was making sense, sure, but that was _his_ job, and it was about all that he had left now, seeing as how his _other_ job had become obsolete less than an hour ago.

"Ugh, Sokka! I've told you and I've told the Council, this is the year that solar maximum coincides with the middle of the magnetic pole reversal, so it would be super dangerous to be pregnant. We've got enough ambient radiation down here to worry about without having to consider the extra coming in from space! You're a man of science, you know this."

"Yeah, and I'm an expert in the science of little sisters too. And I get it, I wouldn't want to spend the last half of my life taking care of a kid before dying slowly of cancer, but hey, I don't even get to make that choice because I was born sterile!" Not that he'd have to actually carry a child, thankfully, that was women's work, but it was the principle of the thing.

"And you think that because I was born fertile I have any more choice? Stop acting like a child."

"I haven't been a child for almost three years, Katara! Maybe it's time you grew up too and stopped shirking your duty to our people." Sokka's returning analytical functions warned him that stomping out of there like a child was hardly helping his point, but he needed to be away from her right now before the emotions and guilt caught up with him and dragged him under again.

"Well, it's a bit too late for that now, isn't it?" Katara yelled after him. She knew as well as he did that they needed to get away from here, too, at the very least to find some breathing room to re-evaluate things before heading back to face a bunch of angry councilors and elders. Besides, he was hardly shirking his duty. It had been blown up in his face.

Cold logic did nothing to silence the little mantra of _too late, too late, too late_ that repeated in the back of his mind.

* * *

"Tea?" a disembodied voice spoke, and a cup of steaming liquid appeared at Sokka's elbow. Sokka started, jumping halfway out of the pilot's seat and in the process knocking the titanium mug to the ground with a splash and a clatter. Hot liquid barely missed soaking two photographs tucked in between the controls – two men, young and old, in one and a stately woman in the other.

"I didn't mean to startle you. That was the house jasmine blend. I know you're not supposed to cry over spilled tea, but it's just so … sad!"

If Sokka hadn't known better, he'd have said the ship's AI was crying. This day was getting stranger and stranger; first, a cyborg sentimental enough to keep _photos_ of all things, and now a computer that cared about tea.

"Who are you?" he demanded. Normally he wasn't so jumpy, but today was not a normal day.

"You can call me Uncle."

"I'd rather not," said Sokka. It was a standard honorific for an older male in most Southeast Asian cultures, but the way the AI said it sounded… more personal. And Sokka wasn’t about to address an AI like he would an elder of his people. "Don't you have another name?"

"My name is IROH. Consider me your Interactive Robotic Onboard Helper."

Sokka snorted. "What genius didn't slap an "Automated" on the front and call you AI-ROH. Well, I am a genius, so tell me, AI-ROH, can you get us out of the Strait? Preferably somewhere _not_ the Fire Nations, although I doubt we can avoid the colonies."

"The island of Papua is rarely frequented by Fire Nations patrols, despite the presence of colonies on the northern part. However, this vessel will require refueling to ensure we are able to complete such a voyage."

"Great. And where might we get said fuel."

"Answers often lie closer than we think. The town of Badu is only a kilometer away, with a population sufficient to support the sale of such things as fuel and basic necessities."

"Veto. That's my village and I'm a teenager having a mid-life crisis, so I'll narrow the preferred destination down to anywhere far, far away from here."

"Only by looking deep within yourself can you find out where you are meant to go."

Did this thing only speak in proverbs? And what did that say about the owner of this ship? "Find somewhere within our range where we can refuel," Sokka said after the mandatory calming breaths. 

"Certainly," agreed the AI mildly. "I recommend Aramia Floodplain. The region is rich in agricultural resources as it's ice-free eighty percent of the year, and the scenery is lovely in the springtime!"

"Do we look like tourists to you?" Sokka grumbled, then quickly added: "That sounds fine." He didn't need to get into an argument with a computer. Despite the fact that he was getting ready to do so with the one inhabiting the humanoid body tied down in the cargo bay.

"My young friend," the voice chided, although the tone was almost fond. "Remember, it is often not what is asked, but rather the way in which it is asked that can prompt the response you desire."

Sokka blinked. He hated that he was starting to make sense of what old IROH was saying. "Oh, you need a password."

A benign chuckle. "It's a little more involved than that. I need my nephew's voice key."

Sokka seethed. "You made me go through all that trouble first —"

"Pleasantries are called so for a reason. Sharing tea with a fascinating stranger is one of life’s true delights."

Sokka rolled his eyes hard as he stood up and tapped the console to darkness. "I guess I have to go pay that nephew of yours a visit now, don't I?" he sneered, then heard himself. "Wow, that sounds evil, I swear I'm not the bad guy, that would be dear nephew cyborg."

"Don't hurt my nephew," warned IROH, voice suddenly ringing of steel.

Sokka stopped, spooked, before recovering himself and leaving the cockpit, muttering: "Whatever, it's not like he can feel anything, I bet. Also, you're a weird old AI."

Really weird. Maybe after he dealt with the nephew he should see about reprogramming the AI to a more compliant personality.

… Sokka swore this sounded better when he said it inside his head.

* * *

If Sokka had learned anything since he'd gotten on this boat, it was that the classic cinema solution of cutting off a thumb wasn't going to cut it here.

Ha, ha.

That old AI had really made him anxious if even puns weren't enough to cheer Sokka up right now. Maybe poking at some shiny new tech would put him in a better mood, once he got past the initial unpleasantness of the inevitable organic and inorganic fluids that accompanied adventures in biotech.

The Fire Prince looked to be both half-conscious and half-frozen when Sokka reached him and then made the executive decision to roll the table and its contents into what looked like a cramped combination of a kitchen and workshop.

"Seriously, keeping tools and utensils together?" Sokka mumbled, to give the room another sound besides the anxious twitchings of the Tracker. He clicked the wheel clamps into place and set to perusing the available equipment. Looks like he'd come to the right place, even if it was nowhere near as nicely outfitted as his own lab.

"Not heavy enough to have a metal endoskeleton, unless whoever made you could afford carbon fiber," he commented. Sokka wouldn't put it past the Fire Nations royals to have top-of-the-line mods and enhancements, but again, the puzzling lack of the famed eye gave him pause.

Sokka couldn't afford to pause for long; it looked like his subject was starting to regain consciousness. He quickly peeled off the layers of reinforced clothing until the prince lay bare-chested on the table; the cyborg was actually trembling, either from cold or the activation of an advanced subroutine to try and trigger an empathy response. Unfortunately for its programmers, Sokka had zero empathy for non-humans. And little enough for actual people, too, if his sister were to be believed.

The Tracker moaned, and golden eyes fluttered open, even the sighted one still bleary. A padded cuff jerked as he tried to throw up a hand and found the motion cut short. The body on the table stiffened. Sokka nervously thumbed at the controls of his shock glove, and waited.

The terrified focus of a singular eye met Sokka's suspicious gaze, and a rusty voice broke over a single syllable. "No."

The meaning was clear, across multiple languages, and Sokka drew in a breath he hadn't known he'd been waiting for. Minutely, he relaxed as the tugging on the cuffs died down, the Tracker's stare growing unfocused once more, although the monosyllabic mantra continued, interspersed here and there with a second word: _please_.

Right. Well, either the cyborg was stuck in some kind of rebooting loop akin to a hallucination or this was yet another subroutine meant to disturb less-intelligent beings. Anyway, Sokka was just going to run a standard diagnostic, not scrap the guy for parts. Although he couldn’t say he wasn’t tempted.

“That thing you burned up wasn't important to me, after all,” he said conversationally, to drown out the annoying background noise. “It was the fluid catalytic cracking unit. That was connected directly to the cryo-chambers. So, thanks for that.”

Turning back to the haphazard collection of tools and materials, Sokka started assembling the things he’d need. He told the Fire Prince to shut up but was ignored multiple times; the cognitive units might have been on the ice too long to start working properly right away. Yet another thing Sokka would need to look at, along with what on earth was in that brain cavity to start with.

"I've heard more out of your ship's AI than out of you," Sokka commented, eager to change the depressing atmosphere the room had acquired. "What, Daddy dearest could afford an AI upgrade for your ship but not for you? Ouch."

He found the connectors he was looking for, then glanced back at the Tracker, considering.

"How old are you?" Sokka asked, vaguely wondering why he was addressing the Fire Prince like he would a fellow human. He was a chatty guy by nature, though, so he'd continue rambling even if his bedside manner was wasted on a lab experiment. "You don't have to tell me, I'll find out anyway once I find your port and get you hooked up to the diagnostics unit. Don't suppose you'd help me out and just tell me where it is."

Sokka wasn't surprised when all he got was more of the same noises the cyborg had been making before.

"Whatever." The terror in the voice, combined with the smooth youthful beauty of the unscarred half of the face, would be disturbing had it come from one of Sokka's kinspeople.

Finally pausing to get a good look at his subject, Sokka frowned. He studied the pale torso, a perfect facsimile of that of an athlete in peak physical condition. It had scars, sure, who in this day and age didn't have scars, but these weren't the scars he was looking for. Normally strength mods meant surgical bone replacements, but this subject had never even had his chest cavity opened up. Odd. Had Ozai's people developed some new installation techniques that hadn't been smuggled out yet, or finally developed mods that grew uniformly with their subjects?

"Hey." The echoing footsteps should have alerted Sokka to his sister's entrance, but he started anyway. He blamed it on his contemplation.

"Is he awake?" Katara asked, cautiously. "I hope I didn't give him too much frostbite."

Awkward. Sokka grunted an affirmative to her question, mostly pretending to be busy prepping the diagnostics unit. It was too soon to address their argument, so careful avoidance it would be. 

"He looks so human." Katara continued her pointless commentary, leaning over to get a better look. "Are you sure he's a cyborg?"

"All the evidence points that way. Or did you miss the way he kicked through your meter-thick ice barrier?" Sokka said, passive-aggressively smarter-than-thou because he just _was_.

Katara took it in stride, stubborn as a glacier because _she_ just was. "He doesn't look like the Trackers in the pictures, though. This eye's the wrong color, and I don't think he can see out of it?"

"Tested that," Sokka deigned to allow that Katara could also occasionally be right about things. "He can't. But biotech develops fast, especially in the Fire Nations. Who knows what they've come up with since we leeched the last Cache update."

"Huh." It wasn't a direct contradiction. Reluctant acceptance, perhaps. "Maybe you're right." His ever-generous sister. "You know, without that scar he'd be almost too pretty."

Ugh, and trust siblings to shoot straight for uncomfortable territory right after getting out of a screaming match.

"Oh, then he'd be your type now, wouldn't he," Sokka said snidely. She'd gone there, so who was he not to follow?

Katara, dare he say almost _apologetically_ , disengaged with a chuckle. "I doubt it." However, she wasn't above raising a meaningful eyebrow.

Deciding to be the bigger man, Sokka ignored it. Besides, even if Sokka stooped to the level of common dimwits and acquired a _type_ , the musculature on this Tracker's unit was clearly in proportions too ideal to not have been extensively engineered.

"Well, I just stopped by to see if there's any food in this place, I know how you get after an episode," offered Katara after another round of stubbornly refusing to say what she actually meant. "Pantry must be somewhere else, everything here looks like poisonous chemicals."

She set down a jar full of some fleshy red-tinged thing, wrinkling her nose in disgust.

"The stomach cavity in a cyborg chassis doesn't get wasted on seven kilometers of intestines," Sokka said, grudgingly accepting her gross olive branch. He definitely _could_ eat, and the only reason he wasn't complaining about hunger right now was that he was gloved up in preparation for the inevitable encounter with weird cyborg fluids. "They don't consume the same stuff we do," he summed up for clarity.

Katara, who'd looked almost like she wanted to give the red jar a second chance, just nodded at that. "I'll leave you to it, then." Sokka got a hesitant half-smile as she walked out, and waved a farewell. Unnecessary waste of time as that social nicety was, he trusted his sister to understand what he was trying to say.

Now if only he could get the Fire Prince to say something more informative than _please, no_. Was there a problem with his speech centers? That could explain why he'd said so little during his attack on the lab.

He'd know as soon as he found the port. The sooner he got this subject hooked up the better, those stupid golden eyes were weirdly effective when glistening with synthetic tears, and Sokka prided himself on his resistance to sympathy plays. Especially from modded-to-the-gills devil-children.

"I've heard about you, you know," he rambled as he searched. It was usually near a vertebra for easy access to the central nervous system, but some more traditionalist engineers sometimes placed the ports nearer to the head. "Quite a few stories floating around for the last three years. You're a Tracker, and with you it’s an accurate description. You may be an elite super-soldier like the rest, but you’re actually hunting something, aren’t you? And either you lost that eye or you never had it. The Fire Lord's spawn, on some secret mission while his heiress sits pretty behind rad-absorbers at home. They say she's the one to be reckoned with, but they also say that when you get violent, not too many live to tell about it. Makes sense I suppose, since apparently you can somehow _burn people alive_. Guess I was lucky, heh. Got a kick-ass younger sister with a powerful mutation. Never thought I'd have that in common with Ozai's firstborn science experiment."

Sokka caught sight of a dull shine beneath black hair and pushed the short, shaggy locks aside. No wonder he'd almost missed it, the giant mass of scar tissue over what remained of an ear made it a bit hard to discern what was going on over there. Finally with a clear view, Sokka let out an annoyed breath and a curse. The port was behind and slightly below the burnt ear, mangled almost beyond recognition.

Heaven forbid that a simple diagnostic could be _easy_. Sokka eyed the half-melted port and pondered the very fundamentals of engineering. Making up his mind, he lined up the connector directly above a 1.5mm flathead and prodded at the spot until he was able to jam it in. "Disgusting," he muttered, glad for the gloves protecting his hands from whatever dark red hydrocarbon-based fluid was beginning to drip out of the area.

Sighing, he slapped on a clamp for good measure so that the connector wouldn't slip out with a good head shake. Machines that weren't half organic. Was that too much to ask?

Looking up, Sokka was pleased to see that information had started scrolling across the monitor screen. "Gotcha," he announced. If the cyborg wasn't going to use his voice talk to him, at least there were ways around that. “Test results are in. You’re a horrible person. We weren’t even testing for that.”

He chuckled at his own cleverness, the paused the monitor on the header information. "Sixteen-year-old cis male, sterile, son of Ursa and Fire Lord Ozai, DNA base configuration is a fire mutation, pyrokinetic in nature.” He snorted. “Yeah, sure, I believe that. There’s got to be a better explanation… where’s that mod list at…”

It was probably taking a while to load, with abilities like this one's it had to be meters long. Sokka skimmed some other header information in the meantime, excited to finally be getting somewhere. "Huh, that's nice, you've got a name. _Zuko_. I'm surprised, I thought Ozai would be more of the type to call you guys _Thing 1_ and _Thing 2_. Could there be even a speck of humanity in that asshole…" Sokka's voice trailed off as he took in the next line, the Zei Humanity Factor.

This number was a compilation of factors, including the percentage of genes that had branched off of the pure _homo sapiens_ variety, the types of necessary mods, number of biotech enhancements, and the like. While the Earth's population as a whole had been sliding slowly downwards on that scale for the past five generations, the average ZHF still remained above seventy percent; anything significantly below that was considered more machine than man. Sokka himself, a product of the fairly pristine UrOceanic gene pool, had ZHF of eighty-seven percent.

Zuko's ZHF was eighty-three percent.

Collins' sacred _sequence_.

"Fuck," Sokka breathed, looking at the trembling mess of Fire Prince bound to the table beneath him. "You're _human?_ "

**Notes for the Chapter:**

> Remember Book One Sokka, at the very beginning? Who hadn't had his doctor-recommended dosage of Respect Women Juice? Yeah, that's the guy who's currently narrating the story.
> 
> Oh, and Francis Collins is usually credited with being the first person to sequence the human genome.


	3. Up to the platform of surrender

"He's _human?_ " Katara stared down in horror at the not-cyborg. _Zuko_. The human Prince of the Fire Nations, Zuko.

Sokka tugged at the short sides of his ponytail and nodded sharply before resuming his pacing. "Numbers don't lie."

"Sokka, why did you stick a screwdriver into the side of his head if he's human!"

"I didn't know, and I wasn't the asshole who melted his port!" Sokka shouted in self-defense, finally plopping down onto the stool in front of the monitor. The small room was not built for pacing. "Which is, by the way, something that a lot of humans with a ZHF that high don't even _need!_ Damn it, where's that mod list. I'm sure it's no big deal, he's got to have a pain mod … bloody hell."

"Do I even want to ask."

"He doesn't have a pain mod."

"Sokka, take the screwdriver out!"

Sokka had enough empathy to wince as he vetoed that order. "I can't, just yet." Scrolling through the information at a manic place, he tried to put into words his sister would understand. "We need to establish some form of communication, since the AI needs his voice signature before it'll take us out of here. And it looks like someone went through his cybernetics BIOS with a sledgehammer, the data flow is absolutely wrecked. Not to mention some of his human brain functions seem to have a cognitive dissonance with his directive programming? Which he has, creepy as that is, but I guess that’s Fire Nations ethics for you. Honestly it's not surprising that he currently has the speech level of a three-year-old, his cerebrum is so cross-wired it barely knows what to do with itself!"

"He's _human_ , Sokka, it's called _trauma_."

Sokka briefly entertained that possibility, but the picture forming in his mind was a software issue, not a psychological one. If that really was a complicating factor…

"This is _why_ I don't take on organic projects!” he complained. “ _Mechanical_ engineer, Katara. Mechanical, and I try to stay hard south of the biomech border." As impossible as that was in this day and age.

"Can I at least put him under while you work on this?" Katara had pulled a medical kit out of some cabinet, and was eyeing its contents.

"No, sorry, if he's asleep I can't test if his speech capabilities are improving. Isn't there a numbing spray or a local somewhere around here?"

"Just hurry up then, Sokka,” said Katara, sifting through the bag. “The last thing we need is for him to come fully conscious and start shooting fire again before we have time to explain."

Which of course made it the perfect moment for the incoherent whimpering to transform into yelling.

Sokka cursed and had to remind himself that the restraints _would_ hold; no amount of thrashing was going to change that. Right?

"I'd be willing to skip the anesthetic and go back to sedatives," Sokka suggested, scanning subroutines for tangles. Which could definitely go faster, but there was a very loud, dangerous distraction at his elbow that was hampering his concentration. Talking himself through it helped, so Sokka kept up a running commentary as he narrowed down the possible causes of the speech impediment. Nice of whoever had been in here before to give such wide-ranging group permissions so that Sokka didn't need a root password, but also creepy as hell. Did the Fire Nations not believe in autonomy or privacy?

Caught up in his work, Sokka didn't even notice when the yelling stopped.

"English?" asked a hoarse, unfamiliar voice, breaking the silence that had settled.

Sokka jumped, glanced at the now-still form on the table, then turned to lock eyes with his sister. "Why would he think we're speaking English, I am only a passive consumer of English, my mouth does not work that way." He guiltily switched from Yumplatok to Mandalay for that last phrase, belatedly realizing he hadn't been using the regional trade language, just as Katara said condescendingly: "Your technobabble's chock full of loanwords. Speak Bahasa Hanyu, genius."

Sokka rolled his eyes at her use of the formal name for the common creole. As a connoisseur of puns in many languages, Sokka preferred the blend of the English words for standard Chinese and Malay, which together also named an ancient city in Myanmar.

"Where are we?" was the next thing out of the Fire Prince's mouth, and Sokka honestly couldn't tell if that was an improvement on their previous seven-word conversation, so he went back to patching the relays connecting human thoughts, cybernetic keyword filters and decision trees, and biomechanical speech systems, while Katara answered.

"About a kilometer outside the Badu Island, on the north edge of the Torres Strait Ice Sheet. Your ship inconveniently re-parked itself after breaking our village dome, which I'm sure you'll get a bill for later by the way, but since we're not exactly interested in company that's okay with us for now. You know, since _we're_ the ones who will get in trouble for the effective genocide your little fireworks show caused." And damn, Katara could be as salty as the ocean when she chose to be. "So, if you'd please tell your weird ice-barge ship-thing to _get us out of here_ , I'm sure we'd appreciate it very much."

There was a pause. "Yip yip," said the Tracker, and yup, Sokka's last tweak had definitely made things worse.

Without warning, the rumble of engines started resonating throughout the small ship, and Sokka looked up from the monitor. "Uh, what?" was his eloquent contribution to their increasingly hard-to-follow conversation.

"I don't want to hang around here any more than you do."

Now that was a full sentence that was worth a full stare from Sokka. And a small internal fist pump at getting so many words, albeit simple ones, from their captive.

"It's because I said please," Katara claimed helpfully, as the view of the ice sheet outside the thick window started sliding by.

Sokka snorted, ignoring her to poke at the fire. "'Yip yip'? Seriously? _That's_ the super-secret voice activation command? What do you think this thing is, a giant flying bison?"

Sokka got a glare for his trouble, and an extra one from Katara for good measure. "Stop taking his side, Katara," he hissed at her, annoyed.

Katara sighed and crossed her arms. "Sokka, you've got to know how this looks right now."

"Enlighten me."

"I'm just saying that we probably look like the bad guys right now. I mean, we're the ones who strapped this guy to a table and stuck a screwdriver into his head. That's not a great first impression, if we're going to try and convince him that we're not going to kill or torture him."

"We're not?" Sokka's surprise was mirrored by the Tracker's skeptical expression.

Katara looked like she was trying very hard not to slap a palm to her forehead. "No offense, but I've had a bit more time to think about this than you have. Analyze your memories of the fight. If I can see it, you can."

Sokka would admit that something about that whole scene had been bugging him, besides the blatant disregard for thermodynamics in general. He just wasn't really a fan of how much the implications complicated things.

"If I had wanted you dead, you'd be dead." Zuko took the words out of Sokka's mouth, voice smooth with an undertone of something nasty. Sokka found himself torn, pleased about the vast improvement in vocal quality, yet very unsettled by the actual words.

"Okay, so we're both the bad guys here," he snapped. "Great."

"I'm sorry, did _I_ hijack _your_ ship and tie _you_ up?"

Sokka wondered if his patches had activated a latent sarcasm module, and if so how could he turn it off. "Shut up, it's been one hour since you last committed genocide."

A visible wince. "That was a cryo storage unit that blew up, wasn't it?"

"Yes," snapped Sokka and Katara at the same time, although Katara's glare was arguably more impressive.

"Oops." The Fire Prince studiously avoided eye contact in a way which said he would have been fidgeting if he had a wider range of motion.

"That's all you've got to say for yourself? _Oops?_ " Nice to know that one of the single worst moments of Sokka's life could be summed up in one syllable.

"Well, try putting a sign there next time!" Zuko was back to yelling. "And maybe that should be a warning about what happens when you pick a fight with me." He rattled a cuff meaningfully.

It meant nothing to Katara, who leaned over him, tone both sweet and utterly villainous. "Remember what happened when _you_ picked a fight with _me?_ "

At least now it was firmly established that not a single person here was a good guy.

"Not worried, I can totally take your strength mods offline," Sokka added, since apparently it was okay to threaten Trackers now.

"What strength mods." The metal of the cuffs _squealed_ unnervingly, and Sokka lunged for his stun glove. The Fire Prince grinned.

"Okay. Look. We both said a lot of things that you're going to regret," Sokka spluttered, fumbling with his clumsy fingers that were refusing to slide inside the apparatus. “But I think we can put our differences behind us. For science!”

_You monster_ , he finished in his head. Sokka thought he heard the captive mutter something impertinent along the lines of _who’s going to regret what now?_ , but he was too busy mentally cursing out the Fire Lord's two-hundred-year-old eugenics program that had produced this freak of nature to be certain.

"All right _boys,_ " broke in a frigid voice. "Can we not threaten violence for two seconds. Yes, you too Sokka. Or else I will flood your nostrils and then freeze the water until it expands into your brains and kills you. And I'll do it with the liquids from your stupid pissing contest if I'm feeling particularly nasty."

This, Sokka thought, is why he had no problem mouthing off to the Prince of the Fire Nations. Because he had grown up with _this_ for a sister.

"Is she always this scary?" asked Zuko, after the appropriate time interval required to picture Katara’s very graphic statement.

"Pretty much, yeah."

A snort. "Sounds like my sister."

Awkward silence punctuated their awkward, unspoken truce as Sokka pondered how to make polite small talk with Imperial Trackers. "So, uh, what are you tracking?"

"None of your business."

"I know it's the Avatar," Sokka shot back. He'd had it snarled in his face in a particularly memorable moment, after all. "Why don't you make this easier on yourself and tell us who they are and what you want with them."

Katara, overseeing this semi-civilized conversation, had at least re-sealed the water flasks she wore.

"I need to get my honor back." Zuko was toeing the line of civil with that tone and glare, in Sokka's opinion.

"That's a non-answer," Sokka declared, although something about honor rang a bell. He turned back to consult the screen once more. "Your protocols seem intact, so I don't see what you mean. Although, man have you missed some updates."

"I don't expect you to understand."

Sokka suspected that that imperious tone wasn't something that could be programmed. Too bad, or else he'd be sorely tempted to delete that capability. Oh well, back to intimidation tactics. "Then I don't expect you to be useful any time soon, so we might as well kill you once I can get a good copy on your voice."

"Sokka!"

Sokka really wanted to roll his eyes at Katara's interjection, but he didn't need to make it any harder to bluff than she just had. "Just because he didn't want us dead before doesn't mean he doesn't now!"

"And the way you're talking is certainly helping our chances with that."

"There's no honor in murdering idiots," sniffed Zuko haughtily, before narrowing his good eye to match the scarred one. "No matter how much more pleasant it would make the atmosphere."

Katara, rubbing away the beginnings of a headache, let out a sigh. "Look, if you can just drop us off at some decent-sized population center and then promise not to kill us right after, that would do. We kind of need to get started looking for some way to replace all that lost genetic material, and I'd really prefer a way that _doesn't_ involve harvesting all my eggs."

Sokka never thought he'd be sharing a queasy-disgusted look with the Fire Prince of all people.

"Yeah, what she said." Sokka tried his hardest not to sound sarcastic. He really did. "We'll totally leave you alone then. And even apologize about this whole hijacking-and-kidnapping, we swear it was an accident. We actually don't want to have anything to do with Fire Nations warships. Like, at all."

Wait, that last part shouldn't have been sarcastic. Oh well, it wasn't as if the Fire Prince appeared to have noticed, if the way he was pondering Sokka's statement was any indication. So he could dish it out but he couldn't take it, good to know.

"That's acceptable," Zuko agreed at last, sounding stiffly formal. "You have my word of honor that no harm will befall you until we part ways."

Katara considered, then nodded sharply. "You can have ours, too."

Thanks, Katara, Sokka had definitely not needed to be consulted in making _that_ decision. "Not that we need to give it, we're kind of in control right now," he saw fit to point out, petulant.

" _Sokka!_ " hissed Katara, and _Zuko_ had joined in on that exclamation too, and he definitely felt ganged up on now.

"What?!" Sokka yelled defensively.

"Do you even know how honor works?" asked the constipated-sounding Tracker.

"As a matter of fact, _mister_ , I do," Sokka replied, snippily. "Or did you forget I'm kind of _inside your head_ right now. And I can see that you've got a 'Word of Honor' protocol as one of your primary neuro-link enablers, which are, as you know, by their very nature reinforced by your own base human characteristics. So unless you want all your very necessary cybermed systems to fail and effectively leave you without _any_ cell repair mechanism in this fun outdoor radioactive theme park, you can't go back on that protocol once you engage it."

His rapt audience of two had the audacity to exchange exasperated looks. Which, _why_ , because Sokka was _right_. He could show them the source code if they didn't believe him!

"That's correct on a technical level," Zuko said finally, sounding as if it pained him.

"You'll literally fall over dead in forty-eight hours if you break your word," Sokka summed up, to help those with less advanced cranial capacity along.

"I know," snapped Zuko. "But honor is much more than that! It's not… biomechanical!"

"It's the cornerstone sociological construct of the Fire Nations culture," Katara supplied, somewhat more primly than necessary. "The gold standard that backs their currency, to use an economic metaphor."

"I don't read your nerd books," Sokka grumbled. He liked his sciences hard like he liked his … uh. Back on track.

"You have my word of honor," Zuko repeated, serious. "And you both know what that means. But I don't know what _your_ honor is worth, so maybe you could start with a show of good faith and, I don't know, take this screwdriver out of my head? It kind of stings."

Gold standard or not, Sokka was understandably reluctant to set their recent enemy loose. "Eh, I just need to check up on a few things first…" he bluffed, and it wasn't exactly a lie. He'd really like a long, hard look at, say, the level of deceit Zuko was capable of, either by nature or programming, and a list of weaknesses he could exploit if and when he needed to, and —

"Prince Zuko, there is an incoming message from Commander Zhao." IROH's voice echoed through the cargo, disturbing the three-way dance-around-the-trust-issue-at-hand that had just been warming up.

Zuko said something, tone sour, in yet another English-based creole (Sokka had forgotten the name of the dialect that bomb-crater-turned-Fire-Nations-capital at the end of the Malaysian Peninsula used), and Sokka thought he caught the meaning of it: _I thought we'd lost him_.

Oh, the irony. A Tracker who was himself being tracked?

IROH's reply was too quick to parse, especially as it got talked over from the person at the other end of the line. "It's _Admiral_ Zhao now, old dragon. Power down your engines and prepare to receive a boarding party."

"How nice for you, moving up in the world," IROH started to reply congenially, but the communication cut out abruptly.

"Who's Zhao?" asked Katara, eyes narrow, and that was all it took.

Zuko assured them both, in no uncertain terms, that Zhao was a hundred times worse than the stream of absolute filth Zuko was using to describe him. If Sokka had any doubts before about the effectiveness of his speech patch, he was relieved of them now. And also the tiniest bit impressed, he hadn't known that Mandalay was so versatile. Sokka took a second to cast a triumphant smirk at Katara, who looked like she suddenly preferred the single-word version of Zuko, in order to project a non-verbal declaration of, _trauma what trauma?_ Engineer beats psychiatrist.

Then he looked down, and swore, because that _oh, snap_ he'd heard hadn't been in his mind after all; it had been _metal_ and now the monitor was flickering to black because Zuko was sitting up and tugging the connector and screwdriver out from under his ear with his newly freed hand.

"Word of honor, remember?" Sokka's voice was a lot higher than it normally ran, in his hasty damage control. "Ours too. Umm, yeah, mutual agreement to non-hurting of each other, formally established, effective immediately. And no take-backsies."

"Hold still," Katara was snapping at Zuko with far more composure than Sokka could find right now, in her own form of damage control. "I think I can stop the bleeding…"

Sokka found his eyes so arrested by an intense golden glare that he barely registered Katara's water getting weirdly luminescent. "I'm not asking you to _trust_ me," Zuko declared. "I'm just asking you to work with me. And I know you probably think we Trackers are all the same, but Zhao won't ask before he takes. And he _will_ hurt you."

In the face of a larger threat, it was still human nature to set aside petty differences and band together. The rather extreme amount of evolutionary progress that had been made in the last centuries had done little to suppress that instinct, so Sokka, with a glance at Katara, acquiesced with a stiff nod. 

"All right then." With a casual display of extreme eugenics and a visible hatred for restraints, Zuko yanked on the remaining cuff, twisting it open, and stood up, rubbing his wrist, declaring: "You're my prisoners now."

**Notes for the Chapter:**

> Some comments to myself on this chapter that I thought were entertaining:
> 
> \- 3 chapters into this AU and it's firmly established that every single one of them is a little shit
> 
> \- Katara: can we not threaten violence for two seconds. *threatens violence*
> 
> \- ending too dramatic? considering the next chapter... nah
> 
> Oh, and anyone want to hazard a guess as to what language the Fire Nation Royals speak in this AU? Picturing Zuko and Azula sniping at each other in this language GIVES ME LIFE
> 
> I can hear your concern from here, all of you who've had to play at-home Linux sys-admin.


	4. I was brought but I was kind

The people of the Fire Nations, based on Sokka’s very statistical sample size of two, were a bunch of theater tryout rejects — simultaneously super pissed and very dramatic. How they'd managed to maintain control over almost half of the surviving world was beyond Sokka.

Case in point. Unnecessary dramatic steam and hissing as the gangplank lowered from the bow of the looming ice schooner. Even the weather was showing off, tiny snowflakes swirling about booted feet as the trio marched aboard Zuko’s much smaller ship — or maybe Katara had gotten caught up in the moment and was being a Fire Nation enabler. But a quick glance confirmed that she, too, found the unnecessary backlit cape billowing entirely gratuitous. And so it went on, with unnecessary bionic red eye flaring, and unnecessary shiny-new androids toting unnecessarily big guns marching two paces behind the main guy, probably to allow room for the aforementioned cape billowing.

"Commander Zhao." Zuko's insulting greeting and dangerous posture seemed downright bland in comparison to Zhao's theatrics. Sokka briefly wondered if he should be playing up his role as prisoner and screaming his throat raw or something like that. Or, you know, engaging in some ominous background chanting.

"It's Admiral Zhao," corrected the man, with one last flourish to his blood-red cape. The lack of any form of address to Zuko was notable, but calculated, given the arrogant expression on the face framed by thick sideburns.

"And it's Prince Zuko to you." Zuko stood tall despite the older man's clear advantage in height and breadth; a laudable effort of looming right back at his antagonist.

Laughable, too, like the sum total ridiculousness of all these dramatics, but no one was asking the gallery right now, so Sokka refrained from commenting.

"As you still insist," said Zhao, with a small mocking bow and a facial contortion that could only be described as a condescending leer. He said something else, too, in that odd mutation of English, probably meant to be equally insulting.

Zuko ignored that and switched back to the common tongue in a with all the arrogance of a Parisian addressing a tourist who'd dared to address him in French. Back when France was a thing, of course. "What do you want, Zhao."

Sokka could feel the clenched teeth in that statement, even though Zuko's back was to him, allowing Sokka the perfect opportunity to appreciate the level of sheer over-the-top that was the two insanely sharp swords strapped to his armored back. Not that Zhao's uniform was any less intimidating. Although much more… fashionable? Certainly the unnecessary cutouts in the armor, showing off the latest biotech that Zuko clearly didn't have, were valued for their form over function.

"I'm hurt, Prince Zuko. I was so sure that my visits were the social highlights of your banishment."

Sokka traded a look with Katara at that, not sure if he should be comforted or disturbed by the fact that they had apparently made a deal with a rogue Tracker.

"That's what I'll call the day I _never see you again_."

"Three years away from home have done little to temper your tongue, I see." Sokka was definitely disturbed by the way Zhao was acting as if he owned the place, up to and including Zuko's personal space. "So, how is your search for the Avatar going?"

"What makes you think anything has changed?" Zuko grit out, unwilling to give ground.

Zhao scoffed. "You're only half blind. Surely you didn't miss the great beam of light that split the sky open two nights ago."

"Oh _please_ ," Sokka exclaimed, because he'd finally put that discussion to rest with the elders of his village _yesterday_. "It's called a light pillar. Some light source, usually the sun or the moon but sometimes even artificial, reflects off of horizontal ice crystals suspended in the low atmosphere, and _bam_ , vertical beam of light. Or else it could be a STEVE, depending on your line-of-sight according to direction of travel, and if it were a few years later it would be triple conjunction time and then you'd have your Star of Bethlehem. Did you seriously come here all flavor-of-the-day European colonizer _without even bothering to learn about our climate_?"

"Why, Prince Zuko," Zhao practically purred, sliding past the younger man at an intimate distance that was completely unnecessary given that the cargo bay was the largest room on the ship. "What do we have here? It seems you _have_ found something on your little hunt."

"They tried to steal my ship, Zhao, they're my prisoners."

Only _tried_ , eh? Sokka said to himself, smug, ignoring the sting from the arrogant dismissal in Zuko's tone.

"And not corpses, so I presume they have somewhat of a value to you." Zhao paused, theatrically mulling over some dastardly thought. "I'll take them."

"Haven't you taken enough from me already, you old vulture," Zuko hissed, striding to stand in front of where Sokka and Katara were sitting on the floor, playing the role of captive audience. Theater prop restraints included.

"Admiral," Zhao corrected, voice cold. "Which means that I am free to commandeer any resources I want." He turned halfway, squaring off with Zuko in yet another show of dominance. "Prince Zuko, you know as well as I do that the Fire Nations can win this war. But in what lifetime, and at what cost?”

Zuko bristled, but was otherwise silent as Zhao went on. “The Avatar is too great of an advantage not to pursue. If you have an _ounce_ of loyalty left, you'll tell me what you found. And if you won’t cooperate, then I’m sure I can persuade these prisoners of yours to do so instead."

Sokka suppressed a shiver. Suddenly the threats he and Zuko had been exchanging earlier seemed like a cute little game in comparison.

Zuko was stubbornly holding his ground, despite the way Zhao was leaning over him and practically breathing the same air. “Finding the Avatar is my prerogative, not yours. And these two are mine. Not yours.”

Zhao threw his head back and laughed. It was an ugly sound. "You can't compete with me! I have hundreds of war ships under my command and you? You're just a banished prince. No home, no allies. Your own _father_ doesn't even want you."

Zuko finally broke, giving a half-step backwards and clenching his fists. "You're wrong!" he shouted. "Once I deliver the Avatar to my father, he will welcome me home with honor, and restore my rightful place on the throne!"

"If your father really wanted you home, he would have let you return by now, Avatar or no Avatar. But in his eyes you are a failure and a disgrace to the Fire Nations!"

"That's not true," Zuko hissed, fingers twitching towards his back, their tips beginning to smoulder.

Caught up in the drama — unnecessary drama, and Sokka stood by that — Sokka found himself holding his breath, wondering what weapon Zhao would pull out next.

"You have the scar to prove it."

Suddenly it all made sense, and the little pieces slammed into place with all the delicacy of a sledgehammer. Now that was one hell of a tragic backstory that Sokka maintained was, once again, _completely unnecessary_. Why couldn't they have accidentally kidnapped a normal Fire Nations lackey and not some classic deuteragonist setup?

Who had finally lost his already-strained temper. "Maybe you'd like one to match!"

Zhao grinned. It made Sokka want to wash himself off with Gran-Gran's good soap, and it wasn't even directed at him. "Is that a challenge?"

"An Agni Kai. At sunset."

Sokka felt that his theatrical whisper to Katara was unnecessarily loud, but that seemed to be the way things worked around here. "An Agni what now?"

* * *

An Agni Kai, as it turned out, involved letting their prisoner walk fully armed and half-naked into enemy territory to duke it out with a similarly armed, similarly partially-dressed would-be-prisoner-stealer.

It was small consolation to think that it was probably actually a good thing that Sokka and Katara were so bad at being bad guys.

"How was this a good idea again?" Sokka complained to Katara, who had taken on the job of being Zuko's second, since it seemed that Zuko didn't know any other people who weren't trying actively to kill him. "Because if Zuko loses, we become prisoners for real, and Zhao is definitely the bigger of the two evils, and if Zuko wins, our annoying captor-slash-still-technically-our-prisoner is _not_ conveniently dead?"

Katara shrugged helpfully. "Hey, whatever makes the creepy old guy go away is fine with me."

Spoken like someone who had a glacier at her beck and call. Sokka didn't have that luxury.

"And it's a good thing to know that Zuko's word of honor extends to throwing down for us. We might have lucked out with this one, Sokka."

"Yeah, we're so lucky he hates Zhao more than he hates us."

"Come on, Sokka, you know what I mean. Would _you_ enter a fight to the death to keep a promise you made an hour ago to not let the people who stole your ship come to harm?"

"No, because I'm not a crazy, dramatic _fool_. And there are certainly other factors at work here."

Sokka hadn't had the time nor the privacy to explain to Katara what he'd deduced about Zuko’s situation, but enough had occurred between the challenge and sunset that he could confidently call the whole thing very messed up.

He'd overheard yet another cryptic statement from IROH, too, who had not seemed pleased about the prospect of an Agni Kai.

"Prince Zuko, have you forgotten what happened last time you duelled a master?" the AI had asked. 

"I will never forget," Zuko had answered, and left it at that, either because Sokka and Katara were making no efforts to hide their eavesdropping, or because that was all he had to say on the subject.

He'd had plenty more to say about the details of traditional honor duels, thankfully. The Ten Commandments thereof seemed to boil down to a testosterone fest (although Zuko had said that women could naturally also fight Agni Kais, and Katara had looked far too interested at that) which ended in surrender or death, whichever came first, and was all conducted in a manner vaguely respectful to some ancient Sun spirit.

Katara was his second because of the cranial-fluid-freeze thing probably, which was unfortunately something they couldn't just lead with.

"Although if it weren't utterly dishonorable, I would heavily consider it." Zuko had gotten a dangerous gleam in his eye at that, and the expression on Katara's face was eerily similar.

"We're not the bad guys," Sokka had had to parrot his sister's earlier words back at her.

"But Zhao definitely is, and if you two are looking to improve the world via murder, he's a much better candidate for that than me."

"Right, and I don't suppose now would be a good time to tell us about how your special assignment—" Sokka had busted out the air quotes for that one — "is one you have because you're banished, and also a rogue who doesn't take orders from whatever division of the Fire Nations Armed Forces Zhao is an Admiral of?"

"It's not a good time, and I'm not a rogue. Prince is an equivalent military rank to Admiral."

Right, because clearly that had stopped Zhao from taking all his stuff before, and one out of the two of them had an actual fleet.

"Now’s the perfect time. It's hours until sunset. What else could possibly be on your schedule before _death match at six, dinner after?_ "

Apparently, Agni Kais called for hours of ritual meditation beforehand, and despite watching Zuko for hour after boring hour in order to call his bluff, there had been no bluff to call.

"Zuko can take him," Katara said, now. It was directed at Sokka, but Zuko was emerging into the light of the late afternoon, and Sokka had no doubts that the prince had heard her. He grunted a noise of agreement; whatever was motivating this conflict didn't matter as much as the fact that one outcome was clearly desired over the alternative.

"Look up at the sun," said Zuko, voice oddly peaceful, indicating the sinking orb above them. Katara shuddered instinctively, and Sokka did too, earning them a strange look from their companion.

" _Goigoika nagi_." Katara muttered the heavy phrase in their ancestral tongue.

"It's said to someone about to die," Sokka explained grimly. "To someone who's about to see the sun for the last time. Bad luck."

"Oh," Zuko said, still drinking in the light as if the UV wasn't yet another carcinogen. "It's not that, in my culture. The sun will always rise again."

Well, that might not be true in another four billion years, but Sokka was willing to give that one a pass. "Right," was all he said, and then watched as his sister marched away with the Fire Prince.

The duel itself, it looked like, would be conducted with the same amount of unnecessary flair with which the Fire Nations did all things. In the slick red light of sunset reflected on ice, two kneeling figures faced each other. Long shadows wrapped around them, threw cheekbones into stark relief, turned the valleys of uneven scar tissue and layered metal into dark stripes of warrior's paint. Dying sunlight glinted off of polished weapons and armbands of gold shielding delicate bio-electronics from high-energy radiation.

They say there is a moment of silence, before the storm, but Sokka had never experienced this. His mind was never quiet; there was always input to analyze and outcomes to predict.

Looking at Zhao, the full extent of his biotech modifications no longer hidden by heavy armor, Sokka felt a pang of nervousness. He had no doubts that Zuko could survive on spite alone, if their own violent encounter was representative, but now that he knew just how cyborg Zuko _wasn't_ , he couldn't help but calculate a distinct disadvantage.

Zhao was big, and would have been even without the mods, and in his athletic prime, somewhere in the early twenties, before the human body and whatever mutations or modifications that had allowed it to survive this long began succumbing to the effects of radiation exposure. One of Zhao's arms looked to be fully cybernetic; its hand grasped the handle of a jointed whip crackling with electricity. Across from the Admiral, not yet fully grown, half-blind and with bare flesh far softer than metal, was Zuko, his swords clearly short-range weapons. The fire in his veins ought to carry him through, Sokka would like to say, but as of yet he had insufficient data on Zhao's capabilities to call the match.

He didn't have long to wait. The strike of the gong reverberated, then Zuko struck first.

It was a flurry of motion, swords reflecting light like spilled blood as Zuko attempted to close the range. A crack and a sizzle; Zhao's long whip flashing out from where he stood his ground, catching with a tangled screech on swung swords. Teeth bared, Zhao advanced on his prey.

A sparking segment flew off the tip of the whip as Zuko extricated his weapons, only to brace anew against Zhao's metal punch. The impact threw the younger man backwards with a grunt, but he managed to turn the motion into a controlled slide across the ice, barely out of range of the ever-advancing Zhao.

"This will be over quickly," Zhao intoned, lashing again with the whip, making Zuko dance away from the electrified strands. A web of blue-streaked after-images burned into Sokka's retinas as the game of cat-and-mouse continued. Or rather, cat-mouse and mouse-cat, given the direction the animal kingdom was headed these days.

_Thump, crack, thump, crack_ echoed over the ice as Zhao advanced, step by powerful step, whip snapping. His ranged weapon kept Zuko frustratingly out of reach; but swords weren't Zuko's only weapon.

Fire was the clear winner in this situation, so where was it? Sokka watched, jaw tense, as the flickering end of Zhao's weapon snared Zuko's boot, sending him spinning across the ice. The unforgiving ground smashed one of the swords from his grip.

Zhao had his opening. He rushed in from the left.

The long shadows left by sunset gave fair warning, as did Zhao's heavy gait. But Zuko was down a weapon and his enemy was coming in for the kill. Something came alive in Zuko’s face then, but it wasn’t fear as Sokka might have expected.

Fire ignited, hot and greedy for oxygen. Zuko let out a shout that was echoed by one of pain from Zhao. Sokka watched in mixed awe and horror as Zuko formed whips of his own, unwrapped sheets of flame from his sword, and punched fireballs at the now-retreating Admiral.

The electrified whip gave out against the overwhelming heat, and Zuko continued the assault. Sokka wasn't much of a fighter — something he made a mental note to change — but even he could see how Zuko was more balanced now, stance grounded and confident. Rooted in flame.

With a roar, Zhao flung the remains of the sparking whip at Zuko’s face and charged. He was inhumanly fast, and with a weight that granted him incredible momentum. He barely clipped the dodging Zuko but that was all it took to send the smaller man to the ground. In another instant, Zhao had stopped, turned, and reared back, cybernetic arm poised for the kill.

Sokka hadn’t believed until this moment that a single blow could reduce a person to a fine paste, but that was certainly the direction this fight was going.

But then something happened that was too quick to catch, and suddenly Zuko was the one on his feet and Zhao was lying dazed on the ground, cybernetic arm smoking. A gesture from Zuko and the smoke turned into actual flame.

“Do it!” Zhao snarled, tone contemptuous even now.

Sokka looked away. He might posture and threaten with the best of them, but deep down he knew he didn’t want to witness this, no matter how much Zhao deserved it.

A loud crack rang out into the tense silence, followed by a sizzle and the hiss of … steam? Sokka looked up. The ice by Zhao’s head was steaming from the aftereffects of a fiery impact.

Sokka couldn’t see Zuko’s face.

"That's it?" Zhao sneered. "Your father raised a coward."

"Next time you get in my way, I promise." Sokka could barely hear Zuko, but for the stunned silence. "I won't hold back."

Turning sharply on his heel, Zuko stalked towards Katara and Sokka. A heat haze or a slight trembling of adrenaline hovered about him, as the sun sank the final few degrees below the horizon.

The scowl was still there, Sokka noted, but there was something else, too. A certain confidence – well, of course there was. That was what people looked like when they won a fight, Sokka told himself, ignoring the smaller voice that told him that this was simply how it looked when you did the right thing.

Lost in his examination, Sokka wasn't watching Zhao. But Katara was.

Ice burst up from the ground, quick as her thought; it strained against the impulse of Zhao's vicious roundhouse, cracked against the blade extending from his boot, but ultimately held.

Zuko turned back with a snarl, but Sokka quickly stepped in front of him, reaching for his shoulders to do what little he could to restrain him. Adrenaline was high after combat, he knew, and Zuko wasn't _thinking_. Lucky for him, Sokka always was, and the only weapons that needed to be brandished right now were words.

"So this is how the great Admiral Zhao acts in defeat?" Oops. Sokka could never resist poking things that just asked to be poked. "Disgraceful."

"Even though he's our captor, Prince Zuko is more honorable than you," added Katara. Smart girl, maintaining their cover story, although from Zhao's reaction, her words had cut far deeper than Sokka's.

Katara didn't melt the ice as they walked away, a level of petty that Sokka could fully support.

"Did you really mean that?" There was a distinct note of pleasure running through the hesitation in Zuko's question.

"Yeah," Katara said, as if surprised to find that it was true. "I guess I did."

* * *

They had dinner afterwards.

One might have even called it celebratory, except that they were still three teenagers and every single one of them was ravenous. The atmosphere was companionable only because they were too exhausted to argue, and anyway their mouths were full. Turns out the jars of red stuff _were_ consumable — by Fire Nations standards, at least. They'd opted to skip salting and pickling and gone straight to preserving everything under a layer of chili flakes that meant death to bacteria as well as taste buds.

"So," Sokka said, once he'd achieved the optimal balance between rapid consumption, fanning his mouth, and human speech. "Where are we going now?"

Zuko blinked, spearing another pickled fish with his chopsticks. Sokka's stomach mourned, because it was unfair that Zuko didn't have to take mouth-fanning breaks. "To find out where that light came from."

Sokka shoved another piece of food in his mouth, and the resulting groaning and panting conveyed his reaction appropriately. "You can't be serious," he tacked on, when the ambient air stopped hurting his tongue.

"He doesn't have his _Atmospheric Phenomena for Dummies_ slideshow with him," Katara explained snidely. "Or else you'd get the full treatment."

"You said light pillars could be caused by artificial lights too, right?" Zuko asked. "So maybe there are people there."

Sokka perked up at the prospect of ending this weird and dangerous alliance and getting on with their lives. Besides, he couldn't discount a perfectly plausible scientific conclusion like that. "Maybe," he conceded. "But like I said. Could be a STEVE —"

"Proton arc," Katara supplied the generic name helpfully.

"Strong Thermal Emission Velocity Enhancement," spelled out Sokka, in English, because he could, "Or really any number of things like that that happen at latitudes with ice in the atmosphere and a messed up planetary K-index."

Whatever it was, IROH triangulated the position of its base to lie near the pre-Apoc population center of Darwin, Northern Territory, Australia.

There were lots of people there, as it turned out.

Sokka realized he ought to have specified that he would have preferred these people to be alive.

**Notes for the Chapter:**

> Zhao has Bucky’s Winter Soldier arm and the whip from the bad guy in Iron Man 2? You bet he does :D :D
> 
> I feel that this Agni Kai is always overlooked in Zuko's character arc. It's the only one we see that's not against a family member, and even here he shows mercy. The whole canon episode in general is really big for our understanding of Zuko. I know it's become popular in fandom to have Book 1 Zuko thinking he fully deserves his scarring and banishment, but this is the episode (episode 3! Of the entire series!) where he literally calls his father a fool. I mean. Whatever canon Zuko's motivations for hunting the Avatar are (imho, they are many and varied), it's certainly not because he believes the Fire Lord knows what's best for him or the world.
> 
> Anyway! Time for Uncited Science Fun Facts!
> 
> If you've never lived in cold high latitudes, you're missing out! Ice crystals in the atmosphere do crazy things. Halos, sun dogs, moon dogs, light pillars, etc! 
> 
> These are light pillars:  
> 
> 
> This is a STEVE. Meet STEVE.  
> 
> 
> Gold is an excellent absorber of high-energy X-rays. High-energy particles (especially in space) encountering electronics can cause bit flips which one way to lose a satellite. That's why you make all your systems redundant.
> 
> Oh, and in the previous chapter, Katara was making some pretty thin excuses for not wanting to be pregnant. While Earth-impacting solar storms are far more frequent during solar maximum, sometimes causing the auroral ovals to get pretty near the equator, it's the atmosphere's job (say thank you to the ionosphere) to absorb or trap that stuff. I'm not sure how the magnetic field looks in the middle of a reversal but assuming it remains roughly bipolar, equatorial regions certainly have nothing to worry about.


	5. My sign is vital (part 1)

It was a ghost town, the surface town, wind-hardened crests of snowdrifts adorning skeletons of buildings until only the very tips of the tallest ones showed, jutting out of the curves and hollows like arrows through empty skulls.

Sokka could've sworn that he'd felt the restless spirits long before it even became apparent that there were any.

The howling wind was playing with his imagination, Katara tried to reassure him, but her voice lacked its usual confidence as they set out on foot from the docked ship. Sokka just grunted in response, preoccupied with his thoughts.

Of course there would be no one in the surface town — humanity had long since migrated underground, or in warmer climates behind walls of thick, lead-lined concrete. Those who could afford it, anyway. Wandering groups still walked the northwestern steppes, they said, but here in the South it would always be wiser to avoid the elements, radioactive or otherwise, underneath a dome of ice.

Sokka had the sudden urge to pull down his thick glove, unwrap his forearms and take a peek at the gauge on the devices strapped beneath. He'd spent more time unshielded in the past forty-eight hours than in most of his life to date; making sure the accumulated dosage was still well below one Sievert would be a comfort. Glancing over at Zuko, whose clothing stood out like a drying bloodstain on linoleum, Sokka idly wondered how close to that lifetime limit the Tracker was. He'd seen the protective devices installed in his upper arms, covered with a layer of absorbing gold to prevent unwanted bit flips. Zhao had had them too; it was smaller, more efficient — more expensive — tech than the removeable ones Sokka and Katara wore. None of it could prevent the harsh truth of the irradiated environment: travel was always deadly to those who did enough of it.

Sokka got the feeling that his journey was just beginning.

"It should be right here," the Tracker said, addressing the general vicinity. It held an impressive amount of snow and ice, but little else to speak of.

"You don't say," said Sokka, because it was cold and he was kind of a jerk like that sometimes, if you asked Katara.

He got a murderous glare for his trouble. Amazing how acclimatized to those he'd gotten in the past two days; Sokka barely registered it.

"Did you read the map right?" Katara was now trying to get a peek at the screen of the device Zuko was holding. "I thought you were supposed to be a Tracker."

Katara was also kind of a jerk like that sometimes, although her primary target in the past had mostly been Sokka. Strangely, he wasn't sure how he felt about sharing this dubious honor with the Prince of the Fire Nations.

Zuko was handing out death glares like iodine pills now, to the siblings and his map in equal parts. "The triangulation is accurate to within five meters. I double checked the numbers myself. There's got to be something here. Or under here."

"Or it was _just a light pillar_ , and the sun or the moon made it _look_ like —"

"Don't you think I asked Uncle about that? The sun was in the wrong place and it was new moon. If it was an artificial source, then there should be something relatively close to the surface —"

"Like this?" Katara's voice was far too innocent. Both men had too much experience with little sisters to trust _that_ tone.

The ice groaned and cracked.

"Got bored listening to you two bickering instead of just asking for directions," explained Katara. The supercilious eyebrow cock was, in Sokka's opinion, just mean. "And it's cold out here."

With a final gesture, she opened up a crevasse, revealing broken tunnel far below. A little more concentration and complicated movement formed an icy staircase.

Determined to be unimpressed by Katara's work, Sokka started the descent.

"Before you two leave, we're having a rematch," he heard Zuko declare from behind him.

"On a glacier or under a full moon?" Katara answered sweetly. Dangerously.

"Both."

Sokka shuddered and picked up his pace, eager to get away from their weird pointless flirting. "How does she have so much self-confidence, she's _fourteen_ ," he complained to himself, only a little jealous. That kind of attitude had to be one of the perks of not being genetically predisposed to overthinking everything.

"I think that's a woman thing," said Zuko, seriously.

It was a thought almost as unnerving as the idea of ghosts.

* * *

It was a service corridor of some kind, leading to a filtration subsystem of the main dome. Pushing open the heavy door to the interior, they were greeted by a silence that was not unexpected, but nevertheless unsettling.

Grey light drifted down in shifting patches, the old skylights of clear ice that hadn't been covered by snowdrifts still doing their duty. Smaller, more diffuse light sources shone throughout shadows cast by quiet buildings; the glow of hasty abandonment, machines outlasting their masters.

Sokka ran the numbers quickly. The dome's radius was about five times as big as his village's own. It could support a proportionally large population, a center the size of which he should have heard about, down in this corner of the world.

The silence turned oppressive. There was no reason that he shouldn't know about this place. No reason except one.

"No one's home." Katara's voice echoed, despite the closeness of the building she was peering into.

"Everyone must have left," Zuko said. "Look, part of the dome is collapsed on the other side."

Sokka did not offer his opinion. Katara knew better than to ask.

They moved on.

Quiet buildings, empty streets. The dome still mostly fulfilled its purpose of protection from the elements; it couldn't have been long since the structural failure, because things still looked functional. Liveable.

As they approached the dome's center, the natural focus point and origin for the narrow lanes, Sokka noticed a soft light blinking in and out of view as structures passed between it and them. It added highlights to the flat grey shadows, revealing...

"Soot." There was a furrow in Zuko's brow as he examined the substance on the tips of his gloves.

Sokka grunted, not eager to encounter what they were sure to find next.

"Blood." A gasp from Katara, but it wasn't a sound of shock.

They came across the first body, half-hidden in the shadows. Cold, dry air had preserved its shape but blackened the features. The clothing was blackened by something else.

"How long ago was this, Sokka?" asked Katara.

Given the average yearly temperature and rate of decay, Sokka would say anywhere between ten and fifteen years. He and Katara would have been so small; no wonder they hadn't heard of this community.

The end had come violently, it was clear, yet somehow also without great fanfare. Here one day, gone the next; it was the story of many a town in the first days post-Apoc. Even centuries later, a single system failure could take out an entire habitation, or whole cities could die out due to something more insidious but no less drastic… such as losing the ability to reproduce. But whatever had happened here had come from outside the dome.

"The Southern Raiders." Zuko held up a piece of material, decorated with a Fire Nations symbol. Beneath it, sea ravens flew, black on red.

Sokka had seen that symbol once before. He wasn't prepared to see it again, here of all places.

The walls were too close. There was that light again, just beyond in the open central circle. Sokka stumbled towards it. Air. He just needed some air, something to quiet the rush of thoughts and memories threatening to take over once again … too soon, too soon, this couldn't keep happening, it was all so long ago, and Sokka was over it. He was, wasn't he?

He still had sounds, even with his vision narrowing to that glowing light, and Sokka could hear Zuko's raspy voice, explaining to Katara. Katara, who hadn't seen the flags. Katara, who'd been the one to see Mom's body instead.

"Sokka? Sokka, what is it?" Footsteps pounded the cold ground behind him. Sokka started to run.

"Sokka!"

The central circle was free of buildings, but it wasn't empty. Strangely, the sight of the corpses piled haphazardly was what brought Sokka back to himself. It had been so long ago, it was true, but he hadn't seen any of the bodies. Not even the one that had mattered the most.

No, instead it was the light. It filled Sokka’s vision, glowing softly, a full moon on a winter’s night, round and slightly yellow. It looked, Sokka thought, rather like an egg. He snorted. Trust his _stomach_ , of all things, to be what grounded him.

Katara's broken cry was sharp, behind him, when she saw the bodies. It was followed by a string of curses from Zuko.

"What happened?" Katara demanded, unable to deny the evidence any longer.

Sokka swallowed, finding his voice and thoughts both intact. Small blessings, indeed. "You know what happened," he answered, staring at his own fists, clenching and unclenching. "The same thing that happened to us, five years ago. Only...we never knew what to call them. Until now."

Sokka looked up sharply, meeting his sister's wide, watery blue eyes, before narrowing in on his target. "And we still don't know _why_ they came." His glare was a challenge. "Care to enlighten us? _Zuko_ , son of Fire Lord Ozai?"

The Tracker looked away, to the bodies, then back to the siblings. "They came to your village, too," he stated, uncertain.

" _Yes_ ," Sokka hissed.

A soft whimper escaped Katara's lips without her bidding. " _Mom_. It was… the same people, who did this, they…"

"Sea ravens." Sokka snatched the scrap of fabric from Zuko, holding it up in challenge. "That was their emblem. They came. They were looking for something. Just as quickly, they left. And she was gone, too."

He threw the offending sigil away, hating how it still fluttered slowly to the ground, as if all his anger and vehemence meant nothing to it, in the end. "All that was left was smoke. And blood. _Why?_ "

"I'm sorry, Sokka. Katara. I didn't know —"

"Oh, I believe you," Sokka hit back, fully sarcastic. "Funny that the next Fire Nations soldier to show up on our doorstep is _also_ looking for something. Someone. You know _nothing_ of the Southern Raiders, but you recognize their symbol. Their work."

"I don't! I don't — look, their mission ended years ago, and _I don't know why they were sent_. I don't know why they would — why they would kill everyone in this Dome, but not everyone in yours. I don't know what they were looking for, or if they found it, or why they stopped. But I _am_ sorry. This is… it's so wasteful."

"Right. A waste of precious _resources_ to you imperialistic colonizers. You know, for a second there I almost forgot what you are, but thanks for the reminder."

"That's not what I — gah!" Fire erupted from clenched fists. When he spoke next, Zuko's tone was curt. "Fine then. You know what, I don't care. Blame me for this, blame me for the whole damn _war_ if it makes you happy until I can get rid of you two. Why should you believe me anyway, I'm an Imperial Tracker and the Fire Lord's son. God forbid that I'm allowed to be different from my father."

“Wouldn't you have done exactly the same thing as the Southern Raiders if you'd showed up here on your Avatar quest and these people were alive?” Sokka challenged. “Because that's what you did _two days ago_ at my village.”

“What? No one _died_.” Zuko’s voice was sharp, angry. “And no one here needed to die, either. Most of the time no one even needs to get hurt, and besides, how stupid would I have to be to try and fight off a whole town by myself? Although I appreciate your vote of confidence.”

“None of this is going to bring her back,” Katara’s voice was small, yet more powerful than their yelling. “Let's just do what we came here to do, so we can leave this cursed place.”

“She's right,” said Zuko, after a moment.

“Shut up,” Sokka snapped at him, pressing the heels of his palms to his eyes. “Why don’t we just go back to _silently_ thinking about how much more convenient it would be if the other person were dead.”

“I can do that.” There was a tinge of almost amusement under the grim tone that Sokka detested. It was gone when Zuko spoke next. “You don't have to listen, but. I'm sorry. About your mom. I know…”

The Tracker cut himself off, finishing instead with a simple _I'm sorry_.

Sokka huffed, stored away the data, and returned to the problem at hand. “Well, from the looks of it, if that skylight up there was clear enough and has the right crystal structure, and high winds cleared away the snowdrift, maybe this glowing egg thing was what made your light pillar. Mystery solved, can we please go home now.”

“Wouldn’t that be nice,” muttered Zuko, with the distracted air of someone who had made up their mind to do something incredibly stupid and impulsive.

Sokka’s suspicion was confirmed when the next thing Zuko did was to walk over and _pick up_ the mysterious glowing egg.

**Notes for the Chapter:**

> I am always here for tragic Water Tribe siblings backstory reveals. Everyone loves Sad Zuko, but really there's so much more to Sokka and Katara confronting their grief -- especially when Zuko's around -- than there is to 'Ozai clearly sucks'. For one, the death of their mother in that way was probably extremely common, as opposed to Zuko's clearly uncommon situation, which is a tragedy in itself. And then it brings up so many subtleties of racism, xenophobia, imperialism, blame-the-person or blame-the-whole-people that are just so nuanced and can be treated in so many different ways. I could read that stuff all day, there's just so many ways it could go.
> 
> In my country at least, everyone living within a certain distance of a nuclear power plant gets a prescription for free iodine pills in the event of a meltdown. For water purification perhaps?
> 
> Oh, and one Sievert is the lifetime limit of radiation dosage for astronauts. That's about 100,000 chest X-rays (you get about one every time you fly trans-Atlantic/Pacific)


	6. My sign is vital (part 2)

Being a genius, Sokka sometimes had to remind himself, meant next to nothing if the people around him were collectively in possession of a single brain cell.

With a click and a shudder, the concrete of the central square — circle, technically, all naming conventions aside — started rotating and sinking lower and lower into the ice.

Not a problem, things weren't progressing too fast and the circle was large but not that large, and in a pinch Sokka had the ice stairmaster at his side. He sprinted to the edge of slowly spinning disk.

"Little boost here?" he called, only to find that Katara… wasn't next to him. "Katara?"

"I …" Her voice trailed off, before she set her resolve. "I want to know what happened here. Why did so many people die, what were they protecting…"

Sokka groaned. He understood; their mother had had something to protect, when the Southern Raiders had hit Badu. She'd died protecting them, protecting Katara. Did that make sense of the senseless violence, and could the same be said here, or would they be thrust further into the realities of a cruel world?

Sokka could resolve these thoughts abstractly, given enough time. Katara, he knew, first needed to experience these things for herself.

It was terribly inconvenient at times.

Frustrated, Sokka stomped back towards his sister, sending a searing glare at the idiot who'd nonchalantly decided to ignore the glowing sign that practically screamed _it's a trap_. The full heat of it was unfortunately lost in the growing darkness as the platform descended.

Impassive, though still clearly fuming from their shouting match, if the wisps of smoke surrounding him were any indication, Zuko stood in the center, still clutching the egg. Eventually, its light faded, even as the light from above grew smaller and smaller as they descended.

Finally, the egg was dark, and the platform ground to a halt. Trails of LEDs illuminated, leading away, deeper into a large, cavernous area. The air smelled stale.

Sokka followed the others as they stepped between the small rows of light. Zuko lit a small fire in the palm not holding the egg, the flickering flame not yet finding any walls to reflect it.

A soft _click_ sounded as Katara wobbled, balance momentarily thrown. _Pressure plate._

All three of them moved.

A barrier of fire flared outwards, licking over a similar shield of ice, illuminating the vicinity in a cold gold flood. Sokka had Boomerang out in one hand and electricity crackling in his other, ready for anything.

Out of the darkness, something heavy shifted. A door ground cantankerously aside, the silence of its rails lost to the years.

Fire went out with a breath. Katara fed her water whips back into their pouches, and joined Sokka in a nervous laugh.

They walked through the door, unsurprised now when it rolled shut behind them. A buzz of electricity, and then fluorescent lights flickered to life. 

It was huge, whatever it was. They'd gone down quite a way, so of course it could be, Sokka reasoned. He still couldn't help but be impressed by what he saw. Rows and rows of oblong capsules spiraled along a central column like lines of meticulous beadwork, a small light at the base of each one shining red. Up and up it rose, hundreds or thousands of them.

Well, six-hundred and forty plus-minus twenty of them, Sokka concluded, after a quick count of an eye-level row and some basic geometry. Far above, he could see some areas that had been damaged, like from a scrape of teeth on an otherwise perfect corn cob, its aftermath accounting for the wreckage in a shadowed corner below.

"What is this?" Katara asked, breathless.

A short, bitter laugh sounded from their Fire Nations companion, but there was no humor in his voice. "It's your lucky day."

"So that's where everyone went," Sokka said to himself, finding his feet drawn to the darkened screen of a console.

"They're … people," Katara realized. She sounded faintly sick. "Cryogenically suspended people. Sokka, there's so many of them!"

The console still worked, and Sokka's eyes flew over the initial information, a sinking feeling building in his gut. "I don't think we're so lucky after all."

"Isn't a place like this is exactly what you're looking for?" asked Zuko, still harsh. "It's designed to preserve human genetic material, and geographically close enough to your home to have a high chance of holding people from the same gene pool. Mission accomplished. You can go home."

There was just one little problem with that, and Sokka took a deep breath before he pointed it out. "Yeah but… they're all dead."

It was Katara's turn to swear. His sister never swore.

Sokka could relate. Red light upon red light, life upon life snuffed out instead of being preserved as promised. It was small consolation, he thought, unable to stop flipping through information on the console, that the pictures of the deceased weren’t displayed. It might be an old tradition, so old it bordered on superstition, but … it was his people’s way of things, and the fact that it had been respected was –

Oh God.

Sokka jumped as a photograph appeared in the upper left-hand corner of the display, instead of the usual blank black square. His eyes flicked to the right, even though he told himself the avoidance wasn’t necessary, this person didn’t even look like him or Katara, there was no way they were kin…

_Suspension status: nominal._

"There's someone alive in here," he breathed. "Someone's still alive! Look for a green light!" 

All too grateful for a call to action, Katara and Zuko sprang into motion. Sokka tried to make sense of the organizational scheme of the pods, hunting for the location of this particular one, the back of his mind tingling as it did when he was on the edge of discovery.

"Over here!" yelled Zuko, from where he'd gone to examine the wreckage. Ice snapped and popped as Katara descended; she and Sokka reached the rubble heap at the same time.

"But _how_ ," Sokka protested, seeing the faint green dot shining steadily from underneath what looked like, for all intents and purposes, a trash pile. Yeah, there were about twenty possible explanations simultaneously gaining or losing traction in his analytical centers at the moment, but the human instinct of disbelief had won out this time.

"I don't know, let's just get them out!" Katara cried, brow furrowed in concentration as she used a slab of ice to push away the remains of what might have also been a pod once. The small light shone stronger.

Sokka might not have elemental control or a hundred-year-old eugenics program lending him extra strength, but give him a lever and he could move the world.

… And get his feet all tangled up in the aftermath of moving the world, could Katara not help out a little? Oh right, little sister, of course she couldn't.

She was too busy staring at something else to notice Sokka's plight.

"It's a … a child?" she said.

"They're beautiful."

The hushed awe in Zuko's voice was the last thing Sokka had been expecting from the Fire Prince. "Stop doing that," he hissed, finally shaking his ankle free of the slippery cable and going over to see what all the fuss was about.

"Doing what?"

"Ugh, saying dorky things like that, do you have any idea of what it looks like coming from you and your Fire Nations death armor?" Joining the others, Sokka leaned over the hastily dusted plexiglass pod window. He blinked, seeing the face from the monitor resting peacefully, eyes closed, in full-color 3D. Faint spots of condensation grew and disappeared as slow breaths hit the inside of the glass.

"Anyway, she's like eight, and the correct term is … cute," continued Sokka, not sure why he was still carrying on this one-sided conversation, besides his innate need to be right. "Pretty, at the very outside."

"I know word definitions," Zuko snapped, but he didn't sound offended.

"Context is everything, you still sound weird."

"What happened to wanting to kill each other, I think I preferred that," Katara broke in. "Let's go back to that."

She'd underestimated their stubbornness. "She's at least ten, and either way she's beautiful," said Zuko, arms crossed.

Sokka shook his head, preoccupied with recalling and implementing the correct revitalization sequence but still unable to let the argument go. "You are. So. Weird."

Not his best closing statement of all time, but now things were happening and he didn't need distracting banter anymore. The likes of which he hadn't expected the Fire Prince to be able to dish up, but the universe was full of surprises, and anyway, it wasn't like Zuko was doing it on purpose.

The hiss of respiration equipment was suddenly louder, as the pod's seal popped open. They stepped back, waiting.

It felt like they'd been watching the small chest rise and fall for hours, but it could have only been minutes later that the first other sign of motion came and girl's eyes fluttered open. They were green, and cloudy. An after-effect of the hibernation, perhaps, protection of the delicate rods and cones against a photon-rich environment?

"Poor thing, she must be so scared," breathed Katara, drawn closer by an invisible force.

Zuko reached out slowly, asking: "Can you hear us?"

His fingertips touched dry hair, and a static spark jumped off of his hand. A small hand shot up to grip his wrist, yanking harshly.

"Who _the fuck_ are you?" A high, shrill voice filled the chamber. Zuko spluttered in surprise. "You think you're so tough? Why don't you come over here so I can snap that grin off your face?"

"I'm not _grinning_ ," was Zuko's brilliant protest, lost however under an impressive stream of foul language and bloody threats emanating from the small girl.

Sokka couldn't help it. He started howling with laughter.

This tiny, pale little girl with a bow in her hair had the prince of the Fire Nations in a death grip and was tearing him a new one with vocabulary even the perpetually angry Tracker would be hard pressed to match. Wiping at the corners of his eyes — after the events of the last few days, Sokka was honestly surprised that he could still laugh like that — he asked Zuko: "Still think she's beautiful?"

"Hell yeah, she's amazing," the Tracker replied, with a dopey grin that _absolutely_ did not belong on that scarred face. He was also ignoring the new set of small fingernail prints pressed into his wrist.

"The fuck do you mean, Sparky," raged the little gremlin. "I know I'm amazing, but … oh, _shit_. Did my parents put me into cryo in a FUCKING DRESS?!! Because I was clearly going to wake up and go straight to a dinner party, I cannot believe them."

She had her legs hanging over the edge of the pod now, pressing the bottom of her cybernetic foot along the slick exterior, trying to find purchase. Sokka was no fashion expert, but he was pretty sure that the green garment with the wide divided legs wasn't a dress. Over it, she wore a short tunic that left most of her forearms bare. Like her lower legs, they were covered with extensive yet subtle mods, the biotech seamlessly integrated into her natural flesh, textured and colored to match when necessary.

Batting away both Zuko and Katara, she half-slid, half fell out of her pod. The second her feet touched the freezing concrete, her stance settled, balance acquired, looking almost as combative as her words. "And can I please get some answers. What year is it, who the hell are you schmucks, and how many heads am I going to have to bash in?"

Every eye, save the girl's, turned to Sokka.

"You've been in hibernation for fifteen years, I'm Sokka, that's my sister Katara, and the idiot who sparked you is Zuko. He's … well, I'm sure you can see what he is."

"The fuck I can't, I'm blind, you asshole."

Right. So that wasn't just temporary? Sokka tried to recall the information he'd gleaned from scanning her profile, but he couldn't even remember her name right now, much less her mutation signature, only that it had made him want to look twice. Perhaps he should have.

"Can you tell us what happened here?" asked Katara, gently, always ready to set things back on track. "What's your name? What's your story?"

"I'm Toph Beifong," snapped the girl, hands on hips. "And I'm not telling you anything until you fools tell me what _you're_ doing here. I may be blind but I can see that you're not employees of Aperture Sciences."

Sokka didn't think the child actually presented a threat to them, but anyone who was isolated, cornered and shocked might get violent without warning, as Toph had already proven. Best to satisfy her curiosity first. "We found this place by accident. Something happened —"

"The Southern Raiders," Katara supplied darkly.

"— the Fire Nations happened to this town, which is in the most important sense not there anymore, and then our Fire Nations prisoner-slash-taxi-driver-slash-it's-complicated over there decided it was a good idea to pick up a glowing egg and that's how we ended up down here. At first we thought that everyone was dead because it seemed like all the vital systems were offline, but then we found you. You're welcome, by the way."

"And what are you going to do now, huh?"

"We're not going to hurt you," volunteered Katara immediately, once again making promises that Sokka hadn't necessarily agreed to keep. Sure, Toph looked a lot more harmless than Zuko, but you never knew.

"They're looking for something," Zuko said. "And we have a deal that we'll travel together until we find a population center to drop them off at. You should come along, too. There's no one here anymore."

"Maybe I will." Toph leaned casually against a slab of concrete debris, acting like she had a choice in the matter.

"We probably shouldn't leave you here," Sokka added, dryly. "Unless you prefer ghosts?"

"I might." Cloudy eyes narrowed. "In case you two are looking for … a certain something. You sound like the type to do your research, Sokka. The type who clearly knew how to operate my pod. The type who could just as easily turn the other ones off."

"I'm not a murderer," Sokka protested. Sound logic from the child, though. "We're not looking for _you_." Why they should be — why anyone should be — now that was an intriguing question that he'd love to investigate later. "And shouldn't you be more concerned about what the Imperial Tracker over there is looking for?"

"Nah," Toph dismissed. "Cuz _you_ know what he wants, and it's something that you're obviously not concerned about, so whatever it is I don't factor into it."

"Hah," gloated Zuko.

"Lemme guess, he's the dumb but pretty one, and you're the brains." Toph’s scathing analysis won Sokka's instant respect.

"Hah," he gloated right back, although he could almost hear Katara's eyes creaking in their sockets as they rolled. Yes, Sokka was the brains of pretty much every operation, and he wasn't about to let anyone forget that. "We're looking for seeds. He's looking for the Avatar and is definitely not smart enough to have to worry about." 

"I can still burn you," sulked Zuko, half-heartedly.

Sokka scoffed. "Like that's going to happen. You've practically adopted this kid already. 'She's amazing'." Okay, so his sappy Zuko impression needed some work.

"I don't need to be adopted, I'm older than all of you," Toph declared.

"Well, technically the hibernation slows aging to about one-fiftieth of its natural rate, so we're still older," corrected Sokka, just because.

"Shut it, Snoozles, you're all working for me now, and I say it's been fifteen years since I stepped in a nice sticky mud puddle and if you get in my way of finding the closest one I'm gonna use your decomposed corpse as a lame-ass substitute."

"Is it … too late to put her back?" Katara said what Sokka was thinking.

  
Twin protests, coupled with threats, burst out from Zuko and Toph. Great. Sokka and Katara's two-on-one advantage had just been nullified. The sooner they got away from Zuko, the better. At least they probably would be able to go home soon. This place was the genetic jackpot of the region; other areas of the facility were bound to have exactly what Sokka and Katara needed to re-stock Badu’s bank.

"Not worth it, at this point," Sokka quipped. "Besides, wouldn't you rather show up back home with a new seed stock _and_ a freshly adopted pale cyborg daughter? You'll probably get an award. Woman of the Year!"

Katara's mouth dropped open, and okay, that last remark might have been a little too much. "You," started Katara.

Sokka swallowed. This was neither the time nor place for a Signature Rant, but heaven help him if he chose now to point that out.

"Are the most. Sexist. Immature, nut-brained —" Flailing expressed what words no longer could. "I'm embarrassed to be related to you!"

Sokka was peripherally aware of Toph and Zuko backing away to leave him to his fate, whispering all the while. He supposed he kind of deserved it, but his brain was many, many times the size of a nut, so that remark was uncalled for.

"Ever since mom died, _I've_ been doing all the work around the house while _you've_ been off playing mad scientist! I even wash your mouldy petri dishes! Have you ever smelled your month-old armpit bacteria colony? Let me tell you, _not pleasant!_ "

Sokka heard a sharp crack echo with her verbal lashing. He looked up. "Katara, settle down!"

Something was wrong. A rumbling noise came next, and …

"Hey, not to interrupt what Sparky assures me is healthy sibling bonding time, but can whoever's doing the thing where they're breaking up the ceiling cut it out? We're kind of under a whole bunch of —"

A final crack, and shards of ice rained down from the edges of a new light source. Sokka didn't have to look up to know what had happened.

"Oops." Katara had the grace to look chagrined. "My bad."

"This way!" shouted Zuko, grabbing Toph and pulling her towards a dimly lit emergency staircase. Sokka and Katara quickly followed, Katara doing what she could to stop the tons of ice above them from losing their battle with gravity.

It was a long way up. The crack widened as a large chunk of ice crashed to the floor below, scraping dozens of pods off the central column as it went. Its rumbling fall drowned out the pounding of their feet on the metal stair, the harshness of their breaths in the cold chamber. Up and up they went, legs and lungs starting to burn now in equal parts, as they struggled against time and gravity.

They were tantalizingly close to the ground level of the dome when the cracks spread to the wall supporting the staircase. Sokka barely had time to curse before the section he'd just sprung clear of sheared off into the depths below.

"Jump!" called Katara, and he followed her on instinct.

Leaping _into_ an ice crevasse was, under normal circumstances, not recommended by the Antarctic Safety Authority of the Torres Strait Ice Sheet. Fortunately they were almost level with the bottom of it, and even the blind girl barely stumbled upon landing.

"Now what?" Sokka demanded. What a terrible day to leave his ice climbing axes at home. Along with all the other specialized equipment they'd need. What a terrible day to leave his home behind, in general. Except technically that had been yesterday.

"Hang on," muttered Katara, calm once more. A series of footholds, uneven but serviceable, sprung out of the sheer sides. Fine for her, Sokka supposed, but how were the rest of them supposed to … oh.

Zuko was already making his way up, Toph on his back, balance assisted by the occasional flame dagger digging into the wall. Well, at least they didn't have to leave her behind. Sokka started after Katara, using Boomerang as a makeshift axe when needed. Against all the odds, they were almost out of here without a scratch.

Odds, in Sokka's scientific experience, did not like being trifled with.

"Wait!" called Katara. The glow from above was bright, and so tantalizingly close, but Katara was staring at a chockstone in the crevasse. At the person-shaped outline stopping the light from above from piercing the glass-clear ice. "There's a boy in the iceberg!"

**Notes for the Chapter:**

> Zuko @ Toph: Hell yeah it's my trash gremlin soul sister
> 
> Me, “fact-checking” this chapter: Cows are spherical, bones are cylindrical, get the resonances from Bessel functions, oh yeah Toph can totally shake her own bones apart. In case you were wondering what actual science goes into writing this. (I am a lot more careful read: actually do research when I write about cultural practices, such as the avoidance practices briefly mentioned here, since I don't want to blindly assume things about other people's traditions)
> 
> Last chapter of the arc should be up tomorrow!


	7. My sign is vital (part 3)

It made no sense.

The ice was transparent, which meant that it had been formed slowly from impurity-free water.

It had managed to wedge itself perfectly into a newly-formed crevasse. These facts, Sokka could explain away with probable physical causes.

He had no answer as to why paths along the boy's limbs and head were _glowing_.

"We've got to get him out of there!" Katara called, already making her way over to the iceberg. From higher up, almost back at the ground level of the dome they'd left what felt like ages ago, Sokka heard Toph yelling at Zuko to put her down and let her see. Which also didn't make any sense, hadn’t she pointed out multiple times that she was blind?

"Katara!" shouted Sokka, following as best he could. "We've got to _go_ , do you have any idea how unstable this ice is? Besides, there's no way he's alive in there —"

As an added exclamation mark, a loud rumble sounded out of nowhere, and out of the corner of his eye, Sokka spotted something large shooting towards him. He ducked, instinctively closing his eyes, and opened them again to —

Right, he was just going to give up on logic now, because clearly it had taken the day off.

Large slabs of stone flowed over the edges of the crevasse, bracing and supporting the icy chockstone. Sokka glanced up, hearing a familiar high-pitched voice.

"Members of the audience, introducing the champion of Earth Rumble Six and you'd best not forget it — the Blind Bandit!"

And he'd thought the Fire Nations were dramatic. Toph was posing in a wide stance, arms raised over her head, silhouetted by the dome's light, which projected her shadow larger-than-life onto the iceberg.

She brought her hands together in a strong movement, and a stone wrecking ball smashed into the ice, cracking it straight down the middle.

Sokka ducked again, avoiding stray shards, then pulled himself over the edge of one of the stone supports and scrambled for his footing. Katara was occupied with thermodynamics-violating changes of phase, and maybe he couldn't help with that but they still needed to get out of here ASAP, because the stone may have stopped moving but the rumbling hadn't quieted.

"Katara!" he shouted again, watching as she leaned over the still figure. It had stopped glowing.

"He's alive!" Her face was radiant as she turned towards him.

"Great, now let’s go — ahhh!" The previously-solid rock beneath Sokka shot upwards, carrying him with it. A twin shout of alarm told him the same thing was happening to Katara; Sokka suddenly regretted not thoroughly reading Toph's mod and mutation specs, because _this_. This was terrifying.

Convenient, though, he amended seconds later, panting on the once-again solid ground. Next to him, Katara struggled to her feet, burdened down with the unconscious body of a boy. He was about Toph’s size, his coloring midway between hers and Katara’s own. Broad blue lines of flexible silicon chips – better known as flex-Si-con — ending in arrows overlaid his skin in thin strips down his arms, legs, and even over his bald head. Sokka had seen bioelectronics like that once before, in a Cache deep-dive that took him back to the very first breakthroughs in wearable medtech.

Just how long had this boy been in the iceberg? 

Far below, the rumbling grew louder.

"Hey, so you all know about fault lines, right?" asked Toph, far too casually for the ominous mood. "Well, there's one here that's not happy, and I can't do anything about that from up here so… someone mentioned a taxi driver earlier?"

As if on cue, the street beneath them cracked in half. Run now, geek out later, Sokka supposed, grabbing the unconscious boy from Katara and scrambling as best he could after the others. An upturned paving stone and the additional weight almost sent him sprawling immediately, but then the ground itself started sliding underneath him, picking up both his companions and a terrifying speed as it rushed forwards. Toph’s doing, if the shit-eating grin on her face was any indication.

Katara took over with barely a hitch once they reached the freezing gale that the surface had become. Sokka bent over the boy, shielding him as best he could with his heavy parka. The blowing snow, together with their speed, obscured his vision to the point where he could barely see Zuko and Toph huddled together on the ice slab scarcely half a meter from him. Sokka did his best to keep the Antarctic wind from stealing his breath, too, and found himself pleasantly surprised that it didn’t sting as much as expected. Maybe he was in better shape than he’d thought.

With hardly a moment to rest since the mad stair-climb that started it all, Sokka almost missed the blinding flash of light that briefly shot through the swirling snow as the dome collapsed behind them.

* * *

The kid had woken up sometime mid-scramble to the ship, but between the howling surface winds and the general urgency of their situation, no one had realized there was a problem until they were all safely aboard.

"You don't speak Mandalay," Sokka said to the boy. Given what Sokka was speaking, the response he got — nothing intelligible, although the language family was vaguely recognizable — was expected.

"Torres Strait Creole?" tried Katara, hopefully. "Bahasa Indonesia? Bahasa Melayu?" 

Sokka shook his head. "Hey, IROH. Any way to tell where this kid is from?"

No answer.

"Zuko, why is IROH off?"

"What do you mean, off?" The Fire Prince's voice drifted over from the cockpit. Very helpful, that guy, as usual.

"Mandarin?" asked Toph, joining in, and finally got a response.

"Who are you?" Sokka understood clearly this time, although he could’ve guessed from the boy’s tone earlier. "What's going on here? Where am I? Do you want to go penguin-sledding with me?"

Sokka blinked. No way had he heard that last part right. "IROH!" Sokka complained, loudly. "We could really use a translator over here, please." He actually could speak Mandarin, but he had a much harder time producing the tonal differences than recognizing them aurally, since his native languages didn't have them. "How good is your Mandarin?" he asked Toph.

"Eh," she shrugged. "I don't _like_ speaking it, but what do you want to tell him?"

"You should probably introduce us all, and let him know he's been in an iceberg for some time. How long exactly, why, and how, I'm sure we'd all like to know."

Toph spoke, and the little _liar_ sounded exactly like the reporters in the newscasts that reached south from Omashu sometimes.

"Nice to meet you!" said the boy, sounding far too cheerful for someone so recently thawed. "I'm Aang! But I don't really know why I was in an iceberg? Or why I'm not frozen anymore, I guess."

His accent was noticeably rougher than Toph's, but he used the language easily enough.

"Hi, Aang," said Katara, using up one of her dozen phrases of Mandarin.

"I can maybe help answer some questions, with a DNA sample," Sokka offered, words stilted but hopefully comprehensible.

"Okay," Aang agreed, but he didn't look too excited about it. Sokka didn't think he would have gone through with it so easily if it hadn't been Katara who passed him the swab and mimed what to do with it. "Are you a monk?" Aang asked hopefully when he was done.

Sokka looked to Toph, whose cackling answered whether or not he'd heard that correctly.

"I know we just met but you don't strike me as the celibate type," she told him.

"Who's celibate?" asked Zuko, done with course-setting and picking the absolute worst time to walk into the conversation.

"Sokka," chorused the giggling women. Sokka hated his life.

"I'm not a monk," he protested, then repeated it in Mandarin for Aang's benefit. "If anyone's the monk here it's Flamey McFlamehands over there, with all his _ritual meditation_."

"I'm Aang, who are you?" Aang asked the new arrival, having not understood Sokka's scathing takedown of the Fire Prince. They were going to have to fix that.

"I'm Zuko," replied Zuko, not even commenting on the fact that apparently they were speaking Mandarin now. "Why were you in an iceberg?"

"Is there a way for the AI to translate or something, I'm a bit lost here," Katara broke in.

Zuko blinked. "Oh, yeah, Uncle ought to be able to get that going," he answered, over Sokka's mumble of _you could have done that five minutes ago when I asked_.

"Well, the last thing I remember, I … well, I'd left the monks and there was a storm …" The last phrase of Aang's got repeated in the common creole, in the voice of a middle-aged woman.

Sokka would have laughed at the incongruity, only he was too busy staring at the first results from the DNA analysis. He transferred his gaze to the boy. "Wow. You're pre-Apoc. Wild."

Aang's brow furrowed. "Pre-Apoc?" The short vowel blend sounded odd coming from him.

"Eh, clever portmanteau of the English terms 'apocalypse', which is a world-ending catastrophe, and 'epoch', which is the beginning of a period in history," Sokka explained rapidly, scanning over the rest of the DNA results as he did so. His own voice got translated in a tone that was a closer match to the real thing.

"Apocalypse?" Aang repeated, distress building in his voice. "What apocalypse? What happened?"

"Well, you know, a kind of salad-bar of classic end-of-the-world scenarios. Climate change, a nuclear bomb here and there, uprisings mixed with large- and small-scale biological and chemical attacks — don't go to the Americas, they're pretty much toast and I've heard there's zombies — humanity being generally dumb selfish assholes to each other."

" _Sokka_ ," scolded Katara, reminding him once again that his bedside manner sucked. Aang did, in fact, look vaguely sick, but Sokka figured it was best to pull off the bandage quickly. What did Katara expect anyway? He could tell this Legends style with the full song and dance, but the end result would be the same.

"We're currently in what you might know as the former poisonous desert of Northern Australia. 'Oh no, why is it a block of ice', you say. Well… I'd tell you to take that up with the Aussies but there's precious few of them left now, the Earth kinda got knocked a bit off its rocker and they're like the new South Pole. Katara and I are from the Torres Strait, which is more of an eleven-months-out-of-the-year ice bridge more than a strait anymore, but you've probably never heard of our Islands."

Yup, from the glassy look in Aang's eyes, he'd definitely never heard of them.

"We prefer to keep a low profile, too, since most of the other islands around the east half of the Ring of Fire got taken over by this one's dad —" Sokka indicated Zuko, who sent him the finger back — "and rumor has it he's got his sights set on conquering the mainlands next. Thing is, he'll have to get past Ba Sing Se to get there…"

Okay, he'd gotten a little off topic now, but he should at least back up and explain basic geography to Aang, who now looked lost in more ways than one. "You hear anything about Korean Peninsula back in your day? Well, the folks up north were the most prepared to deal with nuclear fallout, no surprise, and practically the whole country was a bunker. Still is, only now it's known as the Impenetrable City, and the Fire Lord hasn't found a way to crack it yet." 

"What about the failsafes?" cried Aang, clearly distressed now. "There were failsafes… the monks said… it was getting bad but not up in our mountains, everything was going to be okay…"

Zuko's voice cut sharply through Aang's first sob. "How do you know about the failsafes?"

"Who doesn't?" sniffled Aang.

"That's just a stupid legend," Sokka interrupted, to set the record straight. "If they ever even existed they clearly didn't do jack shit."

"Sokka!" Katara was back to language policing, even though Sokka had no idea how that colloquialism would translate to Mandarin. "He's a kid, there's no need to talk like that. Aang, how old are you?"

"Twelve."

"Well, congratulations, your life expectancy is now thirty," announced Sokka, bitter. "On the bright side, you'll be a legal adult in a few months!"

As expected, this did not cheer Aang up or make Katara any less upset with Sokka. They'd thank him later. Or Aang might, because Katara almost never did.

"But what about the Avatar?" cried Aang, and Sokka could swear he felt his ears physically perk up at that word. "They were supposed to stop this kind of thing from happening!"

Sokka had seen Zuko stiffen to full alert with Aang's mention; now he saw the exact moment when a wave of cold fury washed over Zuko's face. "The Avatar left. When the world needed them the most, they disappeared."

"That can’t be true! Surely the Avatar wouldn’t do that!"

Zuko's voice was cold as ice. "It doesn't matter. Sokka's right. It's just a stupid legend." 

With that, he abruptly turned and left, footsteps ringing on the metal floors, leaving Sokka to wonder if that had truly been the very same Tracker they’d met at the start of this all.

* * *

The group was quick to disperse after that. Katara took Aang to the navigation corner with an arm around his shoulders and promises of videos of penguins on sleds — which begged the important question, why did Zuko have videos of penguins on sleds in his personal Cache — and Sokka remembered that his pondering called for caloric sustenance and went off to the kitchen.

He was just about to risk yet another mystery preserved in chili permanently damaging his taste buds when he heard the distinct sound of someone crashing face-first into … was that literally low-hanging fruit? No, more like low-hanging bulbous root vegetables.

Anyway, there was only one person that could be, and it was confirmed by a long and loud string of age-inappropriate expletives.

"Got any dirt?" asked Toph, when she was done swearing.

"What? No. Like, actual dirt?" Sokka watched her curiously as she navigated the hazardous kitchen-slash-shop with outstretched hands.

"Preferably, but I'll take the hot gossip kind too. So Zuko is the Fire Lord's son eh? Which one?"

What did she mean, _which one?_ "Ozai's only got one son."

"Ozai? Huh." Sokka had to remind himself that Toph’s information was fifteen years out of date. "So Zuko's travelling with his uncle then I guess, but where do you and your sister fit in?"

She picked up a lot more than she let on, Sokka surmised. But then her hearing was probably sharper than most people’s, even unenhanced, to compensate for her lack of sight. "Your leg is twitching, want me to look at that?" he asked instead of answering her.

"That depends, how are you at cybernetics?"

"I'm a genius and a mechanical engineer, I'll figure it out."

Toph laughed at Sokka’s dry sarcasm, then hopped up onto the workbench once she’d found a spot that was clutter-free. Sokka passed her the connector and she skillfully plugged it in to a spot near her T1 vertebra. "Well then, you can talk and tinker at the same time. What's your story? Cuz you're clearly not Fire Nations, and I need to know where I stand on this ship."

Sokka turned to the monitor, while giving her a quick recap. "Zuko burned down my lab, so then I stole his ship, he was our prisoner then we were his prisoners and now we don't actively try to kill each other because word-of-honor. Which, by the way, might not automatically extend to you and Aang, so you might want to check on that."

Toph scoffed. "I can take Sparkle Fingers."

"I just saw you walk into a bundle of turnips," Sokka pointed out dryly.

"Fix up my feet and I can take any of you," challenged Toph.

Sokka snorted. Her readouts were impressive, but she was still a kid. "You may be a cyborg, but you're tech's fifteen years old."

"I'm not a cyborg!" Toph sounded actually offended, for all that she wasn’t employing her usual profanity.

"Uh, your ZHF's forty percent."

"What's that got to do with it? It's just some dumb number made up by an old dead dude. Take five percent off because I was born blind, makes perfect sense. After all, lack of sight makes me so much _less human_."

Sokka had never thought hard about that convention; to him it made sense, since sight was integral to human experience as far as he was concerned.

"And sure I needed new feet and a better endoskeleton, my mutation is based on vibrational interaction, and human bone is a dampener at all the best frequencies and a resonance cavity at the worst. So I get docked another twenty points on a dumb scoreboard so that I can actually use my mutation to do something other than shake my own bones apart? To say nothing of what it takes to survive our radioactive cesspool of a world, not to mention cryo? There’s nothing wrong with a little assistance; what else is technology for?"

She huffed, blowing her bangs out of her eyes, and crossed her arms in a very familiar gesture. Sokka really needed to stop hanging out with opinionated women who liked to rant. “That system is bullshit,” Toph announced. “I know who I am, and I'm not some machine. I'm the world's greatest earthbender and don't you forget it!”

Sokka almost stopped himself from rolling his eyes, but then he remembered she couldn’t see him doing it, so he indulged. “Yeah, well the world's greatest… whatever you call yourself still needs regular system updates, especially after spending fifteen years in cryo, so maybe try being nicer to your local engineer.”

"Well then don't call me a cyborg."

Sokka sighed, recognizing Katara’s stubbornness in Toph’s tone. “Fine,” he grumbled. “Doesn't change the fact that you're a little monster.”

The grin Toph gave him at that was more than a little unnerving.

* * *

There was a problem. A technical problem, which ordinarily Sokka loved, but unfortunately the solution to this one first required human cooperation. Which had been going surprisingly well for the past few hours, all things considered, but still. Convincing less-intelligent people to see that Sokka was right and had been all along was a chore akin to pulling teeth.

Sokka knocked, because it was polite, not because politeness was one of his innate characteristics. One thing it seemed he had in common with the person behind the door.

"Come in," said the rough voice, and Sokka did.

He blinked for a second, taken aback; was Zuko _actually_ a monk? The room was spare enough to be considered ascetic, with only a Fire Nations banner to decorate it. And Zuko was seated cross-legged in front of four candles, which extinguished with a gesture as he stood. "What is it?"

"Two days ago, you were all gung ho about finding the Avatar. Now you say it doesn't matter." And wouldn't that have been more convenient for, oh, say, Sokka's lab if that had happened earlier. "What changed?"

"What's it to you?" Arms crossed, defensive.

"Look, it's all the same to me whether your crazy quest succeeds or fails. But you don't strike me as the type of guy who lacks conviction, so you suddenly giving up is … concerning."

"I'm not giving up," snarled Zuko, as if the words offended him. "It just… look, it's like you said. It's all the same. The world can't be fixed, and… it's all the same." He tugged on a knife that was buried in the wall, a sign of earlier frustrations. Sokka felt his eyebrows raise at the sight of an inscription on the blade: _Never give up without a fight_. Point taken.

"Yeah, to most of the world, I imagine so. But this Avatar hunt means something to you. I'm not _deaf_ , Zuko. I heard what you said to Zhao." Sokka’s stare was a challenge, and Zuko lost it by looking away first.

"Have you heard the stories of Before?” Zuko asked, running a hand through his hair briefly. “How it was…"

"My culture has an extensive oral tradition, I could literally give you the whole song and dance of the last five hundred years." Sokka was quick to clarify a point, just in case Zuko got any ideas. "Katara's more of a dancer than I am, though."

“Huh.” A spark of interest lit up Zuko’s eye at that, but was quickly snuffed out by his previous melancholy. "So you know that… Before… Aang wouldn't have had to… to wake up one day and find out that everything he knows is gone. And in a few months he's out on his own but it's _fine_ because the world says he's an adult, and not… not just some scared kid."

Sokka had a suspicion that Aang wasn’t the only one Zuko was talking about.

"And there's nothing we can do to _fix_ that." Anger had returned to Zuko’s tone, accompanied by a clenched fist. 

Sokka knew that anger intimately. _Not fair, not fair, not fair_ , he heard, resonating in his thoughts and memories. Not fair that Mom was gone, when she and Sokka and Katara had been an actual family. Not fair that their destinies were written from birth, decided by the peculiarities of their DNA. Not fair how most days, survival was the only thing to live for.

A childish complaint, from a childish perspective.

"Yeah, well, we're not children, Zuko. The world doesn't care if it's not fair." It came out more bitter than Sokka intended.

"Even if," Zuko started, low, like it pained him. A confession. "Even if I find the Avatar, it won't help. Father thinks they'll be a tool in his conquest, but he's a fool to think that the other nations would follow him willingly. Avatar or no Avatar."

_In this lifetime or another,_ Sokka recalled Zhao’s statement. _The Fire Nations will win the war._ The only question, it seemed, was the final body count. So what did Zuko want from his own destiny, if not a reduction of that number?

"Besides, he's wanted to get rid of me… ever since… ever since I couldn't …"

Sokka wasn't exactly keen to get to the root of Zuko's clearly extensive trauma-related daddy issues, so he didn't let Zuko finish that sentence. "Hey, buck up. You never know what you'll find, it's a big world."

"Sure, because I'm going to _accidentally_ capture the Avatar."

"Okay, not likely." Sokka had probably deserved that sarcasm. "But in the meantime, it’s not these kids' fault that they're not who you're looking for. Maybe teach Aang some creole and ask him a thing or two about legends. He's more than a hundred years old, and he's a good kid. I bet he'd just really like to get home, too."

"I'm pretty sure it's too late for both of us."

"Fine, be that way," Sokka rolled his eyes, and almost left it at that. "Just don't say things like that in front of Katara. If she even thought that I wasn’t one hundred percent confident that we’ll be able to re-stock our seed bank eventually, she'd go on some two-hour lecture about hope."

Zuko snorted. "Ha. Sounds about right."

"I mean, maybe in a pinch you could pass Aang off as the Avatar, he's pretty ancient right?" Sokka had probably overcorrected on the 'being encouraging' track there, and yup, that totally explained Zuko's horrified exclamation.

"You think I would turn a twelve-year-old _child_ over to my father to be experimented on?"

"Whoa, my bad!" Sokka back-stepped, literally and figuratively. "Of course I didn't mean… I don't want anything bad to happen to Aang either! I'm just not really a motivational speaker, okay, that's my sister.” What had come over him that he was trying to encourage the Fire Prince of all people, anyway?

Sokka cleared his throat and awkwardly changed the subject. “We do need to figure out what to do about these kids. Which is what I wanted to talk to you about in the first place." He fixed Zuko with a hard look, and said it plainly. "Aang's in trouble. His tech is old, like, really old. It's not adapted for this environment, and his genes aren't either. He's from the Himalaya, Zuko. Which means he was even more sheltered than most of the world's population when things started going to hell in a handbasket. If he lasts more than a month, I'll be surprised."

"So he woke up for nothing."

"I didn't say that," hedged Sokka. "What do we have to be proud of these days except for our biotechnical expertise? Humanity's gotten _good_ at fixing ourselves, individually at any rate. We just have to find the right tools that are compatible with his tech." 

"How old are we talking?"

"I'll need to get exact dates out of him once he's coping a little better, but… almost two hundred years."

They were silent as Zuko weighed the number. "It won't be easy," Zuko said, finally, which was what Sokka was expecting him to say. The next part caught him by surprise. "If anyone can do it, though, it's you."

Sokka opened his mouth then closed it again. It wasn't like Zuko trusted _him_. He trusted Sokka, a proven engineering prodigy, to solve a technical issue. That was all it was, it had to be. Just like Sokka could trust Zuko to set anything that annoyed him on fire.

"By the way," Zuko added, looking over Sokka's shoulder now. "Thanks for fixing me. I was … going through a rough patch, after…"

Sure, if 'sudo chmod 777' was what one could call a _rough patch_. Sokka wouldn't do that to his laptop, much less anything responsible for human brain functions.

Clearing his throat, which had suddenly and mysteriously acquired phlegm, Sokka broke his silence. "Listen, I hate to tell you how to adult, but you need maintenance on those mods closer to every six months, not every three years. And Toph could use some updates as well. Getting to a proper facility with the right tools would be ideal for all of you. I don't suppose you know a place?"

Sokka’s eyes followed Zuko’s quick glance at the banner on his wall. "Preferably not too close to the Fire Nations," he added hastily, in case the Tracker was getting any _ideas_.

Zuko's voice was thoughtful. "I have my own reasons for avoiding the Fire Nations, too."

Such as not being allowed there, Sokka thought, recalling the definition of banishment. On pain of death, in most cases — confirmed when he saw Zuko unconsciously touch the side of his neck. So, a kill switch then.

Oh well, if Zhao was representative of Fire Nations thugs, Sokka might as well stay far, far away.

Zuko's gaze was a steady burning flame when it next met Sokka's. "I might know a place."

**Notes for the Chapter:**

> Next update round coming in 4-6 weeks! Thanks so much for reading along and feel free to leave a comment or ask me anything on [Tumblr](https://d-naggeluide.tumblr.com).
> 
> Here's the [disclaimer and works cited list](https://d-naggeluide.tumblr.com/post/616452009626943488/dancer-a-disclaimer-and-works-cited) for this arc, some interesting stuff in there if you're interested in the Torres Strait Islands. 
> 
> Could the earth get 'knocked off its rocker'? Perhaps, but if I never have to solve a spinning top problem in my life again I won't
> 
> For all non-Linux users out there… never run chmod 777 on your computer, please, it basically gives absolutely everyone read/write/execute access on all the files in question.


	8. Dream of home tonight

“Slide!” yelled Sokka, and got an ice ramp. His momentum carried him upwards before his mind and general annoyance with a know-it-all sister could stop him. He just hoped, as he was launched into the air and over a jet of flame – okay, so maybe Katara had saved his skin a scorching by ignoring him this time – that he was able to accomplish his objective before the inevitable bone-crushing landing.

Cold wind rushed past his ears. Almost there…

Sokka twisted and extended his arm, then screamed in frustration as his fingers brushed the smooth green skin of the prize tantalizingly but failed to find purchase.

“Nice try, sucker!” Toph hollered, stamping up a barrier of earthworks that caught Sokka roughly, slamming the air out of him before rolling him down the other side.

“Toph!” he yelled, pounding the dirt with his shock-gloved hand, activating the seismic resonator in the process. 

“I am not Toph!” crowed the blind girl, still clutching the fruit triumphantly. “You thought it was Toph, but it was me, Melon Lord!”

"Do _not_ make me regret pulling this ship over," growled Zuko, hard at work flash-baking and smashing muddy assailants.

A collective groan met his statement. They’d been on the road for almost a week now, and although it might be outfitted with the latest tech, Zuko's ship was _tiny_.

There was the cockpit, barely big enough to hold a pilot and co-pilot, a kind of alcove for a navigator, and then the kitchen-slash-shop, a cramped bathroom, Zuko's room, another room filled with odds and ends that Katara had commandeered for herself and Sokka, and then the cargo bay-slash-armory. There wasn't even a proper engine room; the mechanics were all crammed behind hard-to-access panels, externally mounted, or under tarps on the small deck that held the mast for the albedo sails. It would probably have been a tight fit for the ideal crew of two or three, and they were now three adults and two high-energy kids.

All this meant parking the ship for a minimum hour a day whenever they were over land (this had wrecked Sokka's scheduling, which he maintained despite IROH's insistence on the most random stops, which Zuko indulged in order to pick up knick knacks, but not as much as the ship would've gotten wrecked otherwise) for a cathartic sparring session.

Or, in today’s special edition, petty thievery of a dessert acquired by previous acts of petty thievery.

The original light-fingered thief was Aang, to absolutely no one’s shock once they got to know him. “’My culture doesn’t have a concept of individual property’, my ass,” muttered Sokka, watching the boy flit over ever-changing terrain, keeping Toph busy while Sokka regrouped with the long-range fighters.

“Sifu Melon Lord!” Aang yelled, followed by a peal of bright laughter and another acrobatic series of dodges.

“Oh no you don’t!” snapped Toph. “It’s Lord Melon Lord to you!”

She hurled a series of muddy projectiles Aang’s way, and he kicked a few of them back the same way he would with the worn rattan ball that he’d found on the ship and used to bait people into one-sided games of sepak takraw. The kid was really a mixed bag of the oddest skills, and probably more knowledge than he claimed to have, if you asked Sokka. 

For starters, Aang had the strangest genetic signature Sokka had ever seen. Either humanity had deviated so drastically from its roots in the last two hundred years that their control samples were no longer valid, or there was something very special about Aang. And yet he was the definition of a normal kid, aside from having survived inside an iceberg for the last two centuries. He didn't even know what a mutation was – he thought they all had superpowers like comic book characters – much less have an obvious one. All he would say about the lines of flex-Si-con running along his body was that it separated acolytes from masters. Masters of avoidance tactics, Sokka would say, watching the boy jump over a raised wall of earth as if he weighed nothing.

This was all made even more frustrating by the fact that it didn't seem like it was in Aang’s nature to keep a secret. He’d talk for hours about how to make the fluffiest meringues to top fruit pies with, animals he'd seen and ridden, and the monks at the temple. While Toph and Zuko, the only fluent Mandarin speakers who now acted as Aang’s somewhat reluctant and extremely loud language teachers, were glad for him to get the practice, Sokka just wanted to hear something useful out of the boy for a change. However, Aang was, once they could communicate well enough, kind of a little shit. A sweet, well-meaning little shit, but a shit nonetheless.

He even looked the part currently, covered bald head to booted foot in what Toph would call a healthy layer of earth.

News flash, the Earth hadn't been healthy in a century or two.

"So, what's the plan?" asked Sokka, sliding up to Zuko and Katara on the nice, flat ice sheet he'd wanted all along. "Want me to boomerang it? I could hit it from here."

If he hit Toph while he was at it, well, the little cyborg would be just fine. Probably.

"Don't do that!" Katara looked scandalized, as was her duty as the bratty younger sibling, but she was biting back a smile. "No one wants to eat a broken melon!" 

"Lies," declared Sokka airily, knowing Katara's affinity for fruit smoothies.

"It would be impossible to divide fairly if it were broken," added Zuko, ever serious. "I have a plan, and you each owe me half a share for it."

Right. Just because Zuko didn't sail under the Jolly Roger didn't make him any less of an actual pirate sometimes. "Half a share?" Sokka exclaimed dramatically. "Quarter if the plan succeeds. Failure means Katara and I split your portion."

"Sixty-forty," Katara added opportunistically. "And I'll even chill it for you."

"Hell no, we're in the middle of an ice field, I can cool it down myself! Fifty-fifty!"

"I changed my mind, I'm getting it for myself and no one else," declared Zuko, starting to move.

Sokka threw himself on the other man just as Katara froze his feet in place. "Deal!" they cried together.

"What's this about a deal?!" Toph's shrill voice rang out over the makeshift battlefield. A muddy shape that had probably been Aang half a minute ago twitched on the ground. Some faint gurgles came from him, meaning that he was probably okay and at the worst just choking on his own laughter. "Lord Melon Lord charges a five percent transaction tax on all deals in her realm! Prepare to pay!"

Sokka rolled off of Zuko’s back and slammed his glove to the ground. Toph might figure out a way to ‘see’ past the randomized seismic signals it was generating, but it would take her a hot minute.

“Seven percent!” she shrieked in frustration.

Always business with Toph, Sokka grumbled to himself, although he didn’t hold back his smile. Toph’s parents had been merchants, rich enough to sink a lot of money into her cybernetics and then protect their investment by putting her in cyro. "My parents didn't understand. They always treated me like I was helpless," was Toph’s perpetual complaint, but Sokka had rarely seen a mutation as off-the-charts powerful as Toph’s. Something about her story just didn’t match up.

It was the timing, Sokka realized, calculating ranges and trajectories while Zuko regained his feet after Katara’s hasty thawing of them. Toph was from Gaoling, in southern China, which had been under heavy Fire Nations influence for the past decade. Perhaps, fifteen years ago, Toph's parents had been afraid that the Fire Nations would enact their standard razing-and-colonizing policy, and wanted to spare their daughter that fate. They themselves had opted out of cyro, according to Toph. No greater business opportunity than a war, she'd said bitterly.

Sokka thought there was more than purely business or their family legacy that they'd been concerned about, but if she knew more, Toph was stubbornly silent on the subject.

Not so much now; Toph was happily melon-loguing an improvised economic policy for her new nation, complete with an elaborate and violent system of fines for those who dared abuse the treasury. Sokka had no doubt that she was trying to get a reaction to hone in on their location via sound. He looked up at Katara and Zuko. They were, between the three of them, quite a reactionary group, so they didn’t have long.

"Sokka. Keep that up until we corner her under a drift, then bury her with the boomerang. Katara, I need a banked curve on my mark, then break opposite and get ready to catch."

Katara didn’t even have time for her habitual protest of _I don’t take orders from you_ before Zuko was off.

“Now!” Zuko yelled when he was equidistant from them and Toph, the three of them positioned at corners of a triangle.

Toph crowed in triumph, growing a ridge of rock in Zuko’s direction as Katara bent into motion.

Ice gathered to a glimmering curve, and Zuko flung himself along it, palms aflame. The heat formed a slick sheen of water on the cold surface, and the lack of friction coupled with the propulsion accelerated him to breakneck speed.

Someone was going to get a cracked melon out of this, Sokka could tell. Toph’s rocks were honing in on the icy structure, picking up speed as she worked out the direction. Seconds later, rock met ice with a resounding crack. Zuko was far gone from that portion of the track though, Katara’s path orbiting him a comfortable distance around Melon Lord’s lands. 

If only the little bugger would move, Sokka thought. She wasn’t very tall, so an adjacent snowdrift was all he needed to bury her with the help of a precise boomerang strike. But Toph was stubbornly standing her ground, even under assault from joint forces.

“I have you now!” she yelled, pointing a finger along Zuko’s trajectory. “Time to meet my friend. _The_ _boulder!!_ ”

Sokka’s snowdrift betrayed him by becoming a boulder – or perhaps that snake-in-the-grass had been one all along. It moved ponderously outwards, then suddenly picked up speed, heading onto a collision course with Zuko.

“Do it,” Katara breathed, smooth movements betraying the tension in her eyes as she guided the ice. Sokka grinned.

Just as it was about to blast Zuko off the path, the boulder crashed through the ice-covered ground and dropped out of sight. At the same time, Zuko leapt off a ramp Katara flung up.

Toph only had a second to yell an enraged _fuck you_ at a laughing Katara before she had an armored fire mutant diving for the prized melon. She planted her feet to raise a rock wall, but a wooden staff pulled them out from under her.

“Whoops,” said Aang, white grin gleaming from a muddied brown face.

Sokka collapsed laughing beside his sister. Aang must have used the seismic jamming to sneak up on Toph, who’d forgotten all about him with the flashy fire-and-ice display.

“Heads up!” called Zuko, melon in hand, and Sokka and Katara barely had time to get their feet under them before he threw it.

Katara squawked in objection, but molded an ice channel to redirect its flight; Sokka ran to intercept the falling fruit, going to ground in the slushy snow to cushion the catch.

“Victory!” he declared, whipping out a knife and cracking the rind to dig at the sweet flesh underneath. “One quarter for Aang, five-sixteenths for me and Katara each, one-eighth for Zuko, and none for Toph!”

“HEY!” Toph objected with a stomp of her foot that raised the ground beneath Sokka a good half-meter before dumping him down again.

“You can have some of mine,” offered Katara, generous in victory. “And Sokka’s.”

“Hey!” It was Sokka’s turn to object.

For a patchwork group with varying moralities, the melon got shared pretty evenly in the end.

“So. Zuko,” said Katara, wiping melon juice off her chin. Like the weirdo she was, she was lying on her back on the ice. “Agni Kai?”

It said a lot about the quality of the mock-battle that Zuko didn’t immediately lose it. Sokka snickered to himself; Katara had been asking every day since they’d had the misfortune of meeting Zhao, and the answer she got was always the same.

“No!”

“Can’t blame a girl for trying,” piped up Toph. “Bet I get one before you do.”

Katara snorted. “Get in line.”

“Fight you for it.”

“Why not?”

“I’ll even be nice and take Aang as a handicap.”

“Handicap?” wondered Aang as he was dragged along, getting a hurried translation in the process.

“Keep the dirt out of my solar panels!” Zuko called after them. The west winds had been blowing strongly of late, clogging the ship’s panels with dust. It would undo a hard morning’s work to dirty them now; Toph’s earth manipulation skills, unfortunately, didn’t extend to such fine particles yet, although she said she’d start working on it.

“You should really upgrade those covers,” Sokka commented. “You’d be amazed at the transmission properties of low density polyethylenes. Cheap _and_ easy to clean.”

Zuko grunted an acknowledgement, and stood up. ”Want to go a round?” he asked.

Sokka had mostly spent these pit stops practicing hand-to-hand with Katara or sparring spear-to-staff with Aang, but he hadn't missed the glances Zuko had been throwing at Space Sword.

Not that Sokka would bring out Space Sword for a spar any more than Zuko would use his big broadswords. "Why not," he said anyway, picking up the practice jian that he'd been drilling forms with as a warm-up. "No mods."

"You don't have any."

"So obviously I wasn't talking about myself," Sokka countered, allowing himself a put-upon sigh as Zuko spun the hilts of his day-to-day weapons, extending the blades into their sword configuration as he did so.

"Sure you don't want to fight me with ice axes?" Sokka asked, only half-sarcastic. Unlike Zuko, he hadn't spent every day of his life training for combat, so Sokka could probably use the slight advantage of Zuko having his blades in their climbing configuration.

"Sure you don't want to fight me with half your brain?" returned Zuko, and Sokka barely kept his mouth from dropping open. Had that been… a joke? A compliment? An absurd combination of both?

"First off, my left brain could totally take you all by itself," Sokka started.

"Not true, creativity is a valuable asset in combat --"

"-- and secondly, leave the humor to the pros."

If someone had asked Sokka a week ago what he would do if asked to choose between being outside and behind shielded walls, he would have answered "outside and fighting overpowered mutants" zero percent of the time. But now it was one of the highlights of Sokka's day -- and not only his, he was sure of it.

It was an exhausted group that trudged up the gangway scarcely an hour later; Sokka’s schedule might constantly war with IROH’s zany programming, but the numbers didn’t lie. They were just under halfway into their fifteen-day journey, and it was important to make good time in case things went wrong later.

Call Sokka a pessimist, but he was waiting for the other shoe to drop. Everyone had agreed all too easily to stop actively or passively trying to kill each other, and some of them (Aang and Katara especially) were starting to get downright chummy. Even Sokka could find himself caught up in the camaraderie; it was easy to trade snarky barbs with Zuko or Toph, or to mindlessly lecture Aang and indulge his endless questions when the boy decided to shadow him at the workbench.

Humans were nothing if not adaptable creatures, Sokka mused as he scanned over the logs from his shock glove, making notes about the performance of the seismic generator. He was doing remarkably well without his well-outfitted lab and custom equipment, and he and Katara spent seventy percent of their days within the same fifty square meters without strangling each other. It wasn’t _home_ , but it wasn’t bad either; it was familiar, almost dangerously comfortable.

“Are we there yet?” asked Aang, pretty much instantly after Katara had bullied him out of his muddy boots.

“I regret teaching him that phrase,” called Toph, from where she was sprawled out exhausted in her dirt-corner.

Katara ignored Toph, articulating carefully as she answered. “No, Aang. It’s still a very long way to Baikonur.”

The name itself had a sobering effect on Sokka, breaking him out of reflections by reminding him of the mission. This wasn’t some fun road trip, a coming-of-age story for the kids like in the old movies. No, this was life-or-death for Aang, and for the survival of Sokka and Katara’s people.

Zuko would probably say something about honor here, Sokka thought, and Toph would give that the raspberry it deserved.

None of that changed the fact that this was Baikonur they were talking about.

The mysterious place known in ancient times as Zvezdograd, Star City, home of the Cosmodrome, the world's first, and largest, space launch facility.

The Area 51 of Eurasia, some said, and everyone knew what had come out of the Area 51 of North America.

If Sokka was going to go looking for old tech, there was no better place than where it had all started.

**Notes for the Chapter:**

> I'm back, baby! This arc was a struggle for some reason -- moving on to different fandoms is probably partially to blame -- but it's 90% as good as it can be, and done is better than perfect. Plus I still get shivers reading the last two chapters, so I can guarantee that even at 90% it's gonna blow your socks off. 
> 
> So get ready for 7 chapters in ~7 days (might skip the weekend), and enjoy! 
> 
> Low density polyethylenes = plastic ha ha  
> Also I totally gave Zuko Rayla's swords/ice axes because they're super cool.
> 
> In case you're wondering about my writing process, [here's the original Chapter 8](https://d-naggeluide.tumblr.com/post/622466303676022784/dancer-part-2-deleted-opening-scene) that got almost completely scrapped (I can count on one hand how many times I've done that)


	9. My hands are cold

"I'm surrounded by idiots," Sokka announced a week later, slamming the door shut behind him and nearly barking his shins on yet another random box of crap that was in his and Katara's commandeered room.

Katara just looked at him mildly. "Glad to be excluded from that generalization, brother dear."

Sokka huffed, and didn't exclude her because that would be nepotism and she was part of the problem too.

"Then tell me why," he said instead, "We're parked on the shores of the Aral Sea, less than a hundred kilometers from our supposed objective, and no one has a plan of what to do next, at least that they're willing to share. Because everyone's too busy guarding their precious secrets."

Katara frowned. "Aren't you reading a little much into this? Maybe no one has a plan because no one knows what to do. Toph and Aang are kids, and Zuko may have more experience with this kind of thing, but he's barely older than us, Sokka. And how do you plan for something you don't even know how to ask for, especially when it’s at a place you don’t know exactly how to get to?"

Sokka privately thought more than half their party would resort to brute force to do the former, so what was really bothering him was that they presently had no solution to the latter. Between the Syr Darya glacier and the Aral Sea, which had expanded far past even its original borders before freezing over – a small silver lining to global climate disaster – the terrain was forbidding even for someone who'd been raised on the ice. This glaring obstacle was, however, purposefully overlooked by their friendly neighborhood Tracker. Sokka figured this was the kind of jaded attitude a person could develop after they'd already spent years looking for things that were never meant to be found.

"Zuko knows something," Sokka still insisted. "Look, I don't know what he does during his so-called Avatar research hours, or what's he's got to do with Ozai's aspirations for becoming Asia's Next Top Colonizer. But I can guarantee that there are lots of things he's not telling us, and he's not the only one. And we've all spent almost two weeks pretending that everything is fine, because no one wants to rock the boat!"

"It takes a long time to build trust. Like you said, we've known each other for all of two weeks, and we didn't exactly get off on the right foot with everyone."

Katara implied that they both wanted to and were succeeding in building trust. Sokka wasn't so sure that was a good idea. It would make accomplishing their objective easier, sure, but it would also introduce complications. Dangerous ones, like friendships, feelings of obligation, _caring_ , all those touchy-feely things that would make it so much harder to detach when logic told them they needed to.

"There's too many unknowns," he groaned, kicking a box full of old hard drives. "I don't like it when there's so many unknowns."

Katara clicked her tongue. "You're always saying you're a man of science. Doesn't that mean acknowledging how little we actually know about the universe? Besides," she continued before Sokka could butt in, "We know enough. Aang is a sweet kid despite everything that’s happened to him, Toph's a little hellion but she wears her heart on her sleeve, and yes, Zuko’s an Imperial Tracker, but he has a code."

"I know, I read it." Sokka found his opening with a quip and barreled on. "But that's just the thing. Aang acts like he's not dying and everybody else he ever knew isn’t already dead, Toph seems to think that she's on some life-changing field trip with Zuko, and Zuko pretends like he's got a plan, but if he does he only talks it over with his AI! So what gives?"

"Is it so hard to believe that we're all just trying to cope?" Katara said sharply. "And everyone's got different ways of doing that. You, for example, just love pestering me about all the little details."

Sokka glared at her. He didn't let himself get so weighed down by emotions that he needed to _cope_ , he just was trying to determine a logical plan of action in the face of their current circumstances. Katara, on the other hand…

"Are _you_ okay?" Sokka asked, awkwardly.

Katara sighed, twisting her hands together. "It's a lot, and sometimes I just want to turn around and go home," she started. Sokka bit his tongue to keep from interrupting with the facts. He'd learned by now that she needed to vent just as much as he did, but about feelings and stuff instead. Sokka could tolerate it, but that didn't mean he had to enjoy it.

"But then… it's also exciting, being away from Badu? I know we haven't seen much, outside of each other, but … I've always felt like I could do more. Be more. It still scares me, a little, what I could become, but I know who I am at the heart of me, and … this suits me." She looked up, a little smile on her determined face.

Sokka jerked a small nod. Good for her, and everything. At least her whole self-image wasn't in a shamble along with the wreckage of a freezer. "Well, I don't think this suits me," Sokka said. "I'm an engineer, more than a scientist. I like working solutions, not elegant theories and wild conjectures."

A slight frown flitted across Katara's face before she leaned over and patted his knee. "Hey, don't worry, Sokka. I know you. You'll figure something out."

"Sure, sis." Sokka accepted the platitude for what it was. "Because I always do."

Even if it meant subconsciously hijacking a Fire Nations warship, apparently. And an extremely cramped one at that. Sokka let out a loud breath and stood up. Well, time to go make sure Zuko wasn't planning on ramming his ship into another dome or something equally stupid.

Katara's low voice followed him out the door. "That's what _I'm_ worried about."

* * *

Sokka definitely wasn't the one Katara needed to be worried about. He understood she felt it was her sisterly duty or whatever, but Sokka wasn't currently trying to sneak out onto a frozen sea at the coldest time of night.

No, that would be Zuko.

Sokka let the cockpit chair squeak loudly as it swung around to face the Fire Prince. Okay, so on occasion, Sokka wasn't above his own dramatics. He'd seen enough movies to know this looked cool, after all.

And besides, Zuko's expression was priceless.

"Not up to anything, huh?" Sokka pointedly glanced at the large pack on Zuko's back, and the white camouflage that had replaced his usual red-and-black outfit.

"It's my ship, I can leave it when I want to," Zuko said, defensive.

Sokka grinned, sharp. He had the upper hand and Zuko knew it. "So what's the plan?" he asked.

"Find a way in."

So maybe Katara was right, and Sokka had been grossly overestimating Zuko when he'd expected him to have formulated something slightly more concrete than four words. "And then?"

"Look around. Figure it out from there."

"So you have no plan. Great. Hope that makes you happy, because I'm _ecstatic_." Sokka rolled his eyes.

“If you're fishing for an octopus my nephew, you need a tightly woven net, or he will squeeze through the tiniest hole and escape,” offered IROH suddenly.

Sokka nearly fell out of the chair in shock. “Butt out!” he hissed, just as Zuko honest-to-God pouted: “I don’t need your wisdom right now, Uncle.”

“Yeah, if he was going to do anything wise he wouldn’t be dressed like that,” Sokka remarked to the disembodied AI.

“I'm sorry,” said IROH, but Sokka had a feeling the AI didn’t really mean that. “I just nag you, because ... well, ever since I lost my son ... “

“Uncle, you don’t have to say it,” Zuko interrupted hastily.

Sokka squinted in the darkness, unsure if Zuko’s face was flushed or not. Admirable acting from the AI though, for sure. As if it didn’t launch and kill a million child processes a day. Must’ve been programmed by a real artist.

“Remember your breath of fire,” IROH said, seeming to collect himself. “It could save your life out there!”

“Yes, Uncle,” Zuko sighed, trying his best to turn the lock on the door, but it blinked back to red as IROH overrode the controls.

“And put your hood up.”

“Yes, Uncle.” A hint more of a growl to it this time.

Sokka smirked, and debated whether or not to laugh.

“And take your nice young friend Sokka with you!”

“Yes Unc—what?”

“What?” echoed Sokka.

“You were going to go along anyway,” accused the AI. Apparently, it was a thought-reader now, but Sokka thought about many things before immediately dismissing them as stupid dangerous.

“Was not!” Sokka protested, just as Zuko took objection to Sokka being called his _nice young friend_.

Sokka faked a hurt look in his direction. “I am too nice!”

“You’re not young. Or my friend,” grumbled Zuko in return, tugging again at the door, although he didn’t argue Sokka’s original point.

“Younger than you! Although, old enough to not be condescended to by a machine,” Sokka said meaningfully in IROH’s direction. Or what was the direction of the computing core where IROH resided.

“Ah, the follies of youth…” started the old AI.

“Can we mute him?” wondered Sokka.

“Unfortunately not. Want to get out of here?”

“Sure,” sighed Sokka, despite second-guessing his own judgement for once. He was certain that he’d waited here with the intention of talking Zuko down from great heights of stupidity, instead of getting annoyed into joining in. Yet there was a certain logic to it. Safety in numbers, and the temptation of finally getting some answers – Sokka could see why an AI might come up with that solution.

"Great," said Zuko, although his tone was flat. "But tell your sister first so she doesn't kill me when you end up dead from your own stupidity."

That was rich, coming from someone without a plan. At least Sokka knew the bare basics of survival in extreme environments, which always started with Don't Go Alone, You Idiot.

"So _how_ are we getting there?" Sokka asked, after he'd left a note, because he was smarter than to wake up Katara and let her freeze his feet to the floor. "One does not simply walk into Baikonur."

Zuko's grin was sharp and didn't reach his eyes. "Who said anything about walking?"

* * *

"Okay, so we're paddling. Makes sense. Plenty of meltwater in the channels above the ice that will let a light craft navigate them easily enough," allowed Sokka, huddled up in the bow of the packraft. He pulled the eight-millimeter-thick neoprene hood closer about his ears. It was unfair that the water was definitely warmer than the air, and here he was, dressed for water, yet exposed to the air.

Sokka decided that they were close enough to the dark, seemingly bottomless holes in the ice that he could start pointing out the holes in Zuko's plan. "Cool, cool. Paddling will work _so well_ inside flooded glacial tunnels and caves."

Of course, that was the moment that Zuko chose to dive over edge of the packraft.

* * *

His people had been Islanders, once, and still technically were. The ocean was just… a little more solid now than it had been back in their heyday. So Sokka knew the techniques. He knew that shock was the enemy that stole the breath from his lungs, that freediving under the ice was truly a sport of mind over matter. He knew that he needed to regulate his breathing, keep his heart rate low, and not let the muscles in his torso tense up when he hit the water.

And Sokka knew that doing so was going to be damn near impossible, thanks to Zuko. Had the bastard been pre-breathing the entire time? Sokka wasn't ready, and his adrenaline had just spiked watching Zuko pull his stupid stunt, and it was going to take way too long to get into the state of calm required for such dives.

Mind over matter. The ultimate test, in a way, for someone of Sokka's intellect.

He dove.

Follow the light. Follow the light. Ignore external stimuli. Cold is a construct. The drysuit will maintain necessary bodily temperatures even in supercooled water for up to an hour.

Follow the light.

The entire world narrowed to the soft blue glow of Zuko's headlamp, far ahead.

An eternity of an instant later, Sokka surfaced, and found himself half-crawling, half-hauled up onto a frozen ledge.

He gasped, letting frozen air into his burning lungs. For lack of words, he held up a shaking middle finger in Zuko's direction.

"F-f-f-fff-fuck you," he finally managed. "You asshole." Shit, he was shivering now that he'd let his breath control go. Not good.

Zuko didn't look too much better than Sokka felt, but he was already slowing down his panting. He held up his pointer finger. _One more_. 

"Fuck you," repeated Sokka, with feeling. "I'm feeling very culturally appropriated here."

But hey, at least he got some warning this time, and could pre-breathe. Small mercies.

They did it again. It was even worse the second time around.

Zuko came out on the other side breathing fire, which Sokka vaguely registered was most likely indicative of a deep-seated lung problem. Maybe it was hereditary, so IROH’s reminder to Zuko made sense.

Sokka also noticed that they weren't in a naturally-formed basal cavity any more. He noticed that at about the same time that he noticed the group of armed warriors glaring down at them.

"H-hhh-hi." Sokka's fingers were more spasming than wiggling in their direction. "Nice night for a swim."

Then Zuko attacked, extending his blades and managing one stilted swing, which was impressive given his condition, but it did not impress his opponents in the slightest. A club caught both swords, sending them flying from frozen fingers, and then Zuko was shortly tasting the ice.

So was Sokka, which was rude, because he'd been nothing but the picture of politeness now had he?

From where his face was pressed into the ice, Sokka had a wonderful view of a simultaneously very pissed off and very cold Fire Prince. "You hh-h-happy now?"

"I'm never happy," growled Zuko.

If this was his success record on missions, Sokka could definitely see why.

**Notes for the Chapter:**

> Looks like I'm going to be away from my computer the whole weekend, but this isn't the worst cliffhanger to leave you on, so hopefully everyone's good until Monday :) 
> 
> Thank you everyone for the kind welcome back, it means a lot to me!
> 
> For your daily dose of climate disaster, [here's some satellite images of the Aral Sea](https://earthobservatory.nasa.gov/images/1396/the-shrinking-aral-sea) and its change in area over the last 50 years.


	10. On my knees

"This was a triumph," Sokka told Zuko, making sure to activate Maximum Sarcasm to get his point across. "I'm making a note here, great success. I can't contain my sense of satisfaction."

This earned him twin glares, one from Zuko, and one from the guy who was half-pushing, half-hauling Zuko along. Hell, Sokka would bet that the thug doing the same to him was glaring daggers into the back of his head as well. Three points for Sokka.

The person in charge, a man around Sokka's age with a square jaw and a supremely bad haircut, said something that was probably supposed to be witty.

Witty was Sokka's game, and it was never off, even if he had brain freeze and didn't technically speak the language. He could still recognize the language family (Turkic) and the tone (self-satisfied asshole). This, together with context, led Sokka to deduce that thug-in-charge was very probably calling Sokka some variety of smartass.

"At least I _am_ smart," Sokka shot back, and was rewarded with a stunned silence and a slight pause in his captor's step. And then a blow to the back of the head, because obviously dumbass back there was trying to even out the IQ scales with some permanent brain damage. As if Sokka could ever sink that low.

But hey, if they were nervous now about communicating in their own language, so much the better. After all, they could be worrying about more important things, such as the nature of the device wrapped around Sokka's hand, and oh yeah Zuko had been breathing fire a minute ago, hadn't he? 

Yup, Sokka was definitely going to have to handle this entire situation, because even with his speech paths uncrossed, Zuko was the conversational equivalent of blunt force trauma, and for all that he seemed to be really good at keeping secrets he was terrible at bluffing.

Case in point. "Hi, Zuko here."

Sokka couldn't even blame dumbass-leader-thug from trying to smash Zuko's teeth in for that line. It was _that bad_.

"Sorry about my… companion." Sokka addressed the man who appeared to be the leader. He had a lot of very long, grey, straight hair, both emerging from under his fur-trimmed hat and on his face. They were in an alcove of a large, somewhat cylindrical cavern within the glacier. Sokka did his best to glance around while still giving the impression that the leader had his full attention. This had to be a garage of sorts, given the runners and tracks peeking out from underneath various tarps, and the overall shape of the space which, together with what metal he could see emerging from its coating of ice, suggested that the entire room had once been a vehicle, too – likely of the space-going variety.

Sokka knew the size of the rockets required to send people to the moon, but it was another thing to feel physically dwarfed inside the remnants of one. The small tunnel he and Zuko hade come up through must have been either a natural tunnel that was used as drainage, or had gone overlooked. The presence of a welcome party had Sokka hard in favor of the former hypothesis, and he really hoped it was just mechanical debris they were washing out of here.

"This first date was a real lemon,” Sokka went on. “This one's about as great a conversationalist as Young and Dumb back there." He jerked his head towards Thug Leader.

Thug Leader did not appreciate that comment. Ow.

"Stop it, Hahn," sighed the man, pinching the bridge of his nose in a familiar gesture. Sokka deduced at once that he'd gone grey from pure stress. "We're trying to talk to them, let them keep their teeth for now."

"Or, you know, forever," Sokka mumbled, spitting some blood to the side. Damn, he'd missed getting it all over Thug Crony Number One. "So, how can we help you gentlemen today?" He brightened his tone and gave his best Client Interactions smile to the man with the headache.

This seemed to only increase the headache, if the soft curses in a different language were any indication. "Who are you, and how did you get in here," said the man.

"I'm Sokka, this is Zuko, and we swam here. Clearly. Who are you, or do I just have to call you Headache Guy, Idiot Hahn and Idiot Two?"

Idiot Hahn did not like that, but deferred to Headache Guy's policy of delaying violence until a later point.

"Pakku," said the older man, snubbing both the idiots, probably intentionally. "Tell me why you are here, and remember when you're answering that I'm the one who decides what happens to you for your little break-in."

"Well, you see –"

"We have a kid who needs help," broke in Zuko, ruining everything. "I tried to make contact, but –"

It was Sokka's turn to interrupt and attempt to salvage the situation before Zuko could lie them into an early grave. Seriously, had he been unclear in his telepathic projections of _leave the talking to me, buddy?_

"Kid! Yup, a kid! Not us, personally, just so we're clear. We're more of reluctant situational allies than anything else. So the 'we' is more in the collective sense of we-adults-who-are-in-charge-of-a-child-who-needs-help-which-only-you-can-provide! Let's make a deal."

"Why should I make a deal with my _prisoners?_ "

"Oh, is that what we are?" Sokka gave his most winning grin. It was probably ruined by his bloody teeth. "You know, Zuko and I had that issue not too long ago, and we decided that what was best for everybody was if _nobody_ was the prisoner. Which, if you think about it, would really help the situation here, because then we could just find an arrangement where --"

Hahn must have lost patience at this, or Sokka had reached a pre-established word limit, because he got a kick in the ribs out of fucking nowhere.

"– where nobody gets _hurt_ –" Sokka sent a devastating glare, although the wheezing might have detracted from that somewhat "– and we all get what we want."

"We've already said what we want," said Zuko, and his word limit was supposed to be _zero_ , but Sokka didn't see Hahn kicking _him_ , life was so unfair. "The kid's got old tech, really old, and it's failing. Tech that was first developed here. Now do we have to take it by force –"

Sokka groaned, because Zuko was setting himself on the fast track to becoming the immediate past president of the Being Alive Club, and Sokka did _not_ want to accept the nomination for the position of vice-president.

"– or are you going to tell us what we can do to earn it?"

Threatening Pakku was evidently enough to earn a kick in the back, but at least that kept Zuko from pushing things over the border from bad to worse.

With the situation rapidly deteriorating, Sokka weighed the pros and cons of a dramatically timed reveal, and decided it was what the moment called for. "Hey, it's not like we could just send you guys an email or something. So pardon us the breaking and entering, if you will, and consider that we might actually be able to do you a lot of good." He took a breath, making sure he had Pakku's full attention and minimal annoyance – which appeared to still be quite a bit – before revealing his hand.

"My sister's a powerful mutant. She's got hydrokinetic abilities, and I can't help but notice you live under the ice. In fact, you're fairly lucky we were subtle and didn't just ask her to displace this entire glacier for us to see what's under it." Okay, maybe he was exaggerating a little, but Sokka had full confidence that his little sister could in fact move glaciers. With some additional practice and training.

"Sokka," growled Zuko, and Sokka spared him a glance. "Shut up."

"They were going to find out eventually," Sokka argued.

"It doesn't _matter_ ," hissed Zuko.

"Your friend is right," broke in Pakku, tone still very much put-upon. "So far you have yet to demonstrate that you're worth more to us alive than dead, much less that we should assist you with our technical expertise."

Sokka had the perfect witty response to that, but was deprived of the moment when another man strode in, shadowed by a young woman. The man had the bearing of a leader, wisdom lining his forehead and the corners of his mouth much like Pakku's. The young woman was solemn, and breathtaking; her white hair made the ice around her look dingy in comparison. Silver embroidery on the violet vest buttoned over her white dress brought out her bright blue eyes, which were curiously yet politely examining the newcomers. 

"What's this?" asked the man, and Pakku straightened up just a tad from the whole disappointed, sleep-deprived-teacher slouch he had going on.

"Intruders, Arnook Khan, Princess Yue. They swam in under the ice."

"They must be powerful mutants indeed," said the Princess, her harmonious voice ringing throughout the chamber.

"Why, thank you, we are." Sokka couldn't help but preen a little; it wasn't often that intelligence was lauded over flashy ice powers.

"Powerfully idiotic," butt in Pakku. "They claim to be searching for old tech to help a child in their care, but that explanation is… suspect." The way his eyes narrowed implied exactly in which direction Pakku's suspicions lay. "This is Fire Lord Ozai's son –" he nodded towards Zuko, who glared back at him "– and a companion from the South Pole."

"You know, where I come from, which is the Torres Strait Ice Sheet, by the way, we're pretty geographically relevant. Don't lump us in with the rest of Deep Freeze Down Under," Sokka grumbled.

He was ignored in the favor of the guy who had a fancy title, go figure.

"This is the Fire Prince? The Tracker?" asked the Khan, and his eyes flicked over to Pakku. "We don't want Ozai's attention on us."

"I'm not here to hurt you," growled Zuko. "But I will if I have to."

Once again, the fact that he kept saying things like that was not helping their case.

"I think it might be best if you were never here at all," said Arnook, with a dark threat in his voice that reminded Sokka of deep crevasses. Which could conveniently be used to disappear people even as remarkable as the Fire Lord's son.

"We're not working for the Fire Lord!" Sokka protested. "Like we said, we can _help_ –"

Oh, for fuck's sake, Hahn. Sokka's sentence died as the air left his lungs for the second time in as many minutes. Strangely enough, it was Zuko who was making weird hacking noises and spitting out… gross, was that a bloody molar?

"We're not here on the Fire Lord's behalf," he insisted. "We don't need to be. But you should know." Zuko nodded towards the red-streaked object, which on closer inspection Sokka recognized as one of the buttons from Zuko's coat. It was white, and round, with a lotus flower design. Pakku, too, was looking curiously at it, and crouched down to pick it up.

"Oh my God, don't pick that up, that's disgusting."

Both Pakku and Zuko ignored Sokka's cry. Zuko just locked eyes with Pakku and declared: "He knows about the Moon."

And wasn't that an interesting look Princess Yue was exchanging with the khan. Her father, presumably, who looked… deeply concerned about a fact that was as simple as the _sky is grey from the ashes of a nuclear winter_.

"Take them away," ordered Pakku, leaving Sokka to wonder, for not the first time that day, what exactly had just happened.

* * *

"So, now that we're not freezing to death or getting our teeth re-arranged. Want to tell me what all the flowers and moon cryptic-ness is all about?"

"No."

Sokka knew it was a futile gesture to kick the icy wall of their cell, but he did it anyway. "You really make it extremely difficult to work with you sometimes. I'm pretty sure we want the same thing here, so can you just. Tell me shit, so I can take it into account because let's please remember who's the genius out of the two of us."

He slumped down against the wall, coming to sit opposite the Fire Prince in optimal glowering position.

"I can't tell you because I don't know everything either. Not because I don't want to."

"You were bluffing?" Sokka had to give the guy credit. That took balls, and Sokka's were still frozen from their swim.

"No! I mean, it's true, what I said."

"And you're going to have to explain what you meant by that, because unless these people have legitimately never seen the moon before, you didn't mean what I think you meant," Sokka interjected, but Zuko continued on with his own train of thought.

"The White Lotus, all of that, it's just… sometimes Uncle asks me to do things, so I do them. He doesn't tell me why, and I respect that because it's never too much trouble and he knows best. Besides, it worked, didn't it? It means something, it's a token, just like Uncle said it was. It got them to take us seriously, after all."

"Yeah, taken seriously to jail, probably awaiting interrogation and then execution." Sokka thought about beating his head against the wall, but he didn't want to do his captor's job for them. Zuko, perhaps, could do with having his cognitive capacity re-arranged, though. Did non-genius-level people really trust so much in AIs that they didn't question their judgement?

"Speaking of which," Sokka picked up his previous line of inquiry. "I doubt they're just going to let us go, so how about some fire and then we break out of here? And if you can multitask, tell me about the moon while you're at it."

"I've never broken _out_ of a prison before," said Zuko, a frown in his voice.

Sokka had a bad feeling about that phrasing. "How many have you broken _in_ to?"

"Several."

"Unbelievable." Sokka let his head flop back against the wall. The ice actually felt pretty good on his bruised skull, so he left it there. "How do you usually get out again?" At this point, it couldn't hurt to ask.

"Isn't that why you're here?" Zuko had the audacity to ask. "You're the Plan Guy."

"Once again, _Zuko_ ," snapped Sokka. "How do you expect me to plan things when you insist on withholding information?"

"Fine," grumbled Zuko, squirming in an attempt to get more comfortable on the ice. "I'll tell you what I can, but then you owe me a good plan."

"Fine." Never let it be said that Sokka wasn't confident about his intellectual capabilities.

Several hours later, Sokka could reluctantly agree that Zuko had probably done the efficient thing by not explaining during their frigid canoe ride.

He could even more reluctantly decide on the best plan of action: inaction.

It was, much to his chagrin, a good plan.

* * *

"The Fire Lord knows that the Moon failsafe is located here, in Baikonur," Zuko summarized to Arnook Khan. And, well, when he'd said that to Sokka it had earned a half-hour rant from Sokka about how the failsafes _weren't real_ any more than the Avatar was.

Arnook didn't argue with Zuko's statement at all. Neither did Pakku, or Yue, or any of the other local officials gathered in the small conference room.

Sokka stood corrected.

"Recently, that information reached one of his Admirals – a sycophant who has the resources at his disposal to initiate an attack."

When Sokka had learned this little tidbit about Zhao, he'd understood Zuko's hatred for the man a little more. Not that what Zhao had done to acquire said information in the first place wasn't enough to make anyone's blood boil, but it was probably best that Zuko didn't bring it up here. He'd obfuscated enough in the cell, alone with Sokka who could deduce full well what had happened, but the last thing they needed right now was for the blame to bounce back to Zuko.

"I can't be sure when they're coming, but rest assured – the Fire Nations will attack. And if you help us out, I will make sure that you are both forewarned and know exactly what you'll be facing."

"You would betray your own people?" came Yue's soft voice.

A look of angry frustration crossed Zuko's face. "The Fire Nations need the Moon too, we can't risk the balance any more than you can. I don't know what Zhao is thinking!"

They'd have to be fools to turn this offer down, Sokka had assured Zuko, teeth chattering in the cold of their cell. _Like you are right now?_ Zuko had turned the statement on its speaker, and that was the _only_ reason – besides signs of early-onset hypothermia – that Sokka had awkwardly curled into the fire mutant's side, accepting the offer of shared heat.

"We accept," said Arnook Khan, after a moment's silent communication with Pakku and a glance at Yue. "Pakku is our technical lead, and he will assist you with the children. Master Yugoda, our combat specialist, will train your sister, Sokka, in exchange for your own insight into technological solutions. You'll all be granted access to necessary facilities, with appropriate supervision."

They'd had to tell almost the full story of their adventures with icebergs and frozen children during the course of the negotiations, but in the end Sokka was satisfied with the outcome. Better than being dead, for starters.

"I will do my best to ensure that these conditions are carried out to the satisfaction of both parties," said Princess Yue.

The Khan nodded gratefully at his daughter, before turning back to the Fire Prince. "In return, you, Zuko, will assist us with preparing defensive countermeasures against a Fire Nations invasion force, up to and including detailed information on the military’s organizational structure and weapons capabilities. This is our final offer."

Pakku didn't need to say what refusal would mean, and Zuko didn't need to add any threats to assure them neither side wanted to risk that outcome.

Zuko nodded, the movement sharp. Sokka echoed the movement, and pasted on a broad smile as he took a small bow. "Thank you for helping us help you help us all."

**Notes for the Chapter:**

> I had a hard time finding out information about the structure of the Kazakh Junior zhuz, so I just went with the title of Khan for Arnook cuz it sounds cool. I am definitely open to more accurate suggestions if anyone happens to know. 
> 
> You should look up Kazakh traditional clothing by the way, their women's fashion is top-notch.
> 
> And if you've ever stood beside a Saturn V rocket, you know how humbling that is.


	11. Grace and Virtue

Sokka felt no small sense of justified smugness, watching the glacier (okay, it wasn't the whole glacier, clearly, but a hefty chunk of ice nonetheless) part to let Zuko's ship slide into the interior. Katara could probably do that if she was on a social justice rant of some kind, and knew where to apply pressure.

Watching the elderly woman overseeing both her team and the process with smooth movements – General Yugoda, he remembered Arnook saying – Sokka also felt a vague sense of apprehension, imagining the true terror Katara could be with a little honing of her hydrokinesis. But for now, he'd just be happy to see his sister.

Internally, because he had a reputation as a suave smartass to maintain.

Unlike Zuko, who dashed towards his ship the second its prow crossed the threshold, and jumped onto the gangplank before it was even properly lowered.

Following at a more leisurely pace, for the sake of both his dignity and Princess Yue, Sokka heard the loud sounds of an excited Toph and Aang and the worry-tinged notes of an angry Katara. Yeah, Sokka was going to let Zuko take the tongue-lashing for that one. The icy swim under hostile waters had been his idea after all.

"I'm not saying you'll like them," Sokka commented to Yue, who managed to make even a giggle sound dignified and royal. "But hopefully you won't hate them."

"I must admit I'm very curious to meet the children. It's not often one meets an elder that is actually younger than you!"

"Trust me, they don't act like elders," said Sokka, dryly, and almost got bowled over by the whirlwind that was Aang.

"Sokka! You're okay! Katara was worried. Your scroll said you went hunting, but nothing to hunt!"

"Message, or note," Sokka corrected automatically. "And there's plenty to hunt on the ice if you know what to look for. Aang, this is Princess Yue. Princess Yue, Aang. His creole isn't great yet, sorry about that."

"Honored to meet you!" cried Aang, with a little bow, and Sokka rolled his eyes. Of course with Zuko as a teacher, one of the first words Aang had learned was _honor_. And now the little airhead was using it to show up Sokka's statement about his language capacity.

"It's an honor to meet you, too, Aang." Yue was the picture of grace, and a picture Sokka wouldn't have minded staring at extensively under different circumstances. But what with the looming threat of a Fire Nations invasion, and Sokka about to get yelled at by his sister, that was wishful thinking.

"Sokka, I hope you're –" Speaking of sisters. Katara caught herself with a stutter, cheeks suddenly flushed red. "Oh. H-hello."

"Hi," breathed Yue, and Sokka felt the overpowering urge to hit himself in the forehead, hard. "You must be Katara."

"Yes. That's, uh, that's me. Who are – Sokka, introduce us!"

Since when did Katara care about being proper? Although anyone who looked at Yue could tell at once that she was a dignified woman. Sokka sighed, greatly put upon. "Katara, Princess Yue. Princess Yue, my sister and the occasional bane of my existence, Katara."

Wow, he'd gotten not one but two women to blush at that. He'd be patting himself on the back for his flirting prowess if one of them wasn't his sister.

"You're the hydrokinetic, right? I'd be happy to accompany you to meet General Yugoda."

"How is there dirt fucking everywhere? I was gone for twenty hours, Toph!" A loud argument was making its way out of the ship. Toph's doubtless impertinent answer was, thankfully, muffled by the ambient noise.

"Yes, you little dung beetle, I know _why_ there's dirt. What I don't know is how the hell Katara didn't lay into you for trying that shit!"

"Katara was having a normal emotional reaction to her dumb-as-rocks brother disappearing in the middle of the night in along with a drysuit and packraft!" Katara, suddenly sounding more like herself, turned to shout at the duo. "Which," she said meaningfully, looking back to Sokka. "We are going to have a long talk about later."

Yue stifled what might have been a giggle behind a gloved hand. Sokka rolled his eyes at both their reactions. "Sure, sis," he replied. He did feel kind of bad about the quality of the note he left, which had in retrospect barely covered the extent of the situation at all.

"Please excuse my… directness," Katara was trying now. "I just worry about him when he's being an idiot. So rather a lot."

"Hey, Snoozles is alive too!" Toph trotted blindly in Sokka’s direction and swung a high-five in the approximate area of his face. It might have worked, had there been anyone standing there. "Damn," she scowled. "I fucking hate ice."

"Toph, Princess Yue, Princess Yue, Toph," said Sokka, voice dry, catching Toph's arm to give her a point of reference.

"She's the little turd I told you about, Yue," grumbled Zuko, crossing his arms over his chest and attempting his habitual scowl. Sokka wasn't fooled.

"It's _Princess_ Yue," hissed Katara, scandalized, and still caring more about manners than Sokka had ever witnessed in his life.

Zuko raised a lone eyebrow at her. "And I'm a prince. So we're even."

"Technically," Katara allowed.

"What's a turd?" asked Aang, a linguistic step behind. This earned him actual facepalms from his teachers and a hurried lesson on the extensive module _Common Colloquialisms for Poop_.

Katara, Sokka noticed, was back to trying to play above-it-all, and had taken Yue's proffered arm to go meet the combat master.

"Zuko, didn't you need to meet General Yugoda, too?" asked Sokka, loudly, before turning a toothy grin on his sister.

"Oh. Right. I do. Are you taking Aang and Toph straight to the lab, then?" 

"No time like the present," Sokka shrugged.

"Okay. I'll be by as soon as I can."

"Nah, take your time," urged Sokka. Someone had to keep an eye on Katara, and Zuko at least seemed immune to Yue's feminine charms. A fact which Sokka was not going to analyze extensively, later, by himself. "I'm sure there's plenty you need to learn about. Advanced warning systems, first response protocols, you know. Battle stuff."

"All right." The look Zuko gave him was an interesting one, as if he knew Sokka was up to something but couldn't tell what. It was almost as hilarious as the terrified expression that crossed his face when Zuko noticed Katara and Yue's linked arms. Sokka nearly choked holding his laughter in as he saw Zuko hesitantly offer his arm to Katara, probably in the process of trying to desperately remember if it was some kind of expected royal etiquette. The swiftness and intensity of Katara's rejection might have pleased Sokka more yesterday, but right now the last thing he needed was for some silly infatuation to mess things up. _Looking at you, Katara_ , he thought hard in her direction, to squash down any other thoughts that might have arisen at that. _Looking at you._

* * *

Pakku took one look Aang and immediately started rubbing away a headache. Sokka suppressed the raise of a curious eyebrow. The guy hadn't even met Toph yet.

"Yes, those arrow-shaped overlays certainly resemble some of the first bio-regulatory wearable tech systems that were developed here, but I don't immediately recognize the design. Of course, this was hardly the only hub of innovation at the time, though personal shielding tech first developed here has long since become standard issue. The interface protocols are old, too, as you said to expect. Non-standard, as well, even for the time. Interesting, very interesting…" The older man wandered closer to Toph, who was standing to the side of the examination table with crossed arms and a challenging look on her face.

Suddenly, her head snapped around from where her hearing was focused on Aang, and she stared aggressively at Pakku's chest. "Excuse you, stay the fuck out of my head."

Sokka paused his speed-browsing of the engineering drawings archive and looked over. "You've got some kind of near-field communication capability, don't you?" he asked Pakku. The man's constant headaches now made a lot of sense. Sokka wondered if he had the neural processing capacity to deal with the data rate of the electronics he could communicate with.

"Yes," said Pakku, raising his hands slightly in an attempt to placate Toph. "My apologies. My mutation often triggers unpleasant anti-viral processes in more advanced cybernetics."

"Yeah, no shit, and my system doesn't appreciate you beyond exchanging network protocols, so stop whatever the hell you're doing before I make you."

"So Aang's cybernetics are one-sided, aren't they? Like Zuko's." That would explain why neither cyber-equipped boy had reacted to Pakku. On principle, Sokka thought this was a terrible idea, but on a certain level he could understand why it was done. Neural interfacing was still tricky in this day and age, let alone two hundred years ago, and it was simpler to let the cybernetics run themselves mostly independently than to enable full diagnostics and control from the host.

"What did you say about me?" asked Aang, swinging his legs over the edge of the examination table.

"Your tech," said Toph. "You can't modify what it does, but it regulates you."

"Only certain biological processes, and normally to a minimal degree that you wouldn't notice anyway," broke in Sokka, because Toph had a habit of phrasing things in the worst way possible. "Straight-up behavioral control is considered highly unethical." Even behavior reinforcement was extremely sketchy, but often deemed necessary for regulating dangerous mutations.

"The Fire Nations would seem to disagree," said Pakku, voice dry.

Sokka thought guiltily of Zuko and his strict cybernetic protocols, choosing to dwell for now on the positives: they kept Sokka and Katara safe from Zuko, and evidently they'd been enough to convince Pakku that Zuko had been telling the truth earlier. Rationally, Sokka didn't like what they implied, though. No matter how human Zuko might act, he couldn't be trusted like one. Although if anyone could out-stubborn orders written for him by someone else, it would be the Fire Prince.

"Good thing we're not in the Fire Nations, then," was all that Sokka said, in the end. He turned his attention back to Aang, who was fidgeting with a small tool he'd found lying near the exam table. "So, how should we do this? Are we going to need a wired connection to interface, or is your NFC the best option to check out Aang's tech?"

"A wired connection would be more stable and easier to sustain. Fortunately, port designs have changed very little over the years. I'll have to see if our Cache still contains the necessary drivers, though." Pakku walked out in what Sokka recognized as the absentminded haze accompanying a truly intriguing project. The guards that accompanied them stayed at the door, watching Sokka’s movements but not impeding him.

Sokka left Toph to try to translate the technobabble for Aang, in favor of setting up a quick 3-D print of the connecter design he'd found in the archive. Katara would put him in the deep freeze if he pulled his screwdriver trick again, but fortunately now he had the resources that enabled him to avoid that.

"What do you mean, cybernetics control people?" Aang's normally cheerful voice now sounded upset, breaking into Sokka's concentration. Oh well, he was really just waiting for the printer to finish now anyway. "That's not right! They're only meant to help people!"

"Yeah, well, what if people want to use them to do bad shit?" challenged Toph, interspersing Creole swearwords with the formal Mandarin. "Or if their mutation makes them crazy, dangerous, or crazy dangerous? I mean, we could just let those people die."

"No you can't! The monks said --"

"Survival of the fittest, Twinkletoes. That's kind of the story of the past two centuries, except a bunch of people cheated."

"By mind-controlling other people to fight for them?"

"Technically," interrupted Sokka because he never would not. "Nothing can mind-control a person. The human brain is _the_ original root user. So that's where insidious programming comes in. Using sympathetic logic and feedback to minimize resistance from the human brain. Making someone think the command was what they wanted to do all along, basically."

"That's bullshit," argued Toph. "I do what I want, and my cybernetics do what I fucking tell them. If I don't want to feel how cold this damned iceberg is, they won't. No matter how much they want whatever vibration profile they can infer from this stupid frozen floor to feed into my balance sensors."

"Why do you care if your cybernetic feet get cold at all? They wouldn't send any discomfort signals to your brain unless they were in danger of malfunctioning."

"That's the point," Toph continued. "I shouldn't care, but I didn't always have these feet, and I remember how much having cold toes _sucks balls_. So even though they're programmed to react pretty much like my bio feet did, I don't let them get cold."

"How nice for you," said Sokka. "Let's say someone decided to make them itch until you walked across a bed of hot coals though. Or even just put it into your head that doing that would feel really good. Then what?"

"I do what I want," repeated Toph, stubbornly.

Sokka was beginning to wonder if Pakku's headaches were contagious. "Anyway," he said, pointedly in Mandarin to prompt Toph to summarize the parts they'd slipped into Creole for so that Aang could follow along. "Overriding human will is a complicated topic. In theory, it can't be done purely electronically, but really anything that annoys a person for long enough will probably get them to cave. Although then this all comes back to the definition of human in the first place. Full-on cyborgs don't count of course. The question becomes, where can you draw the line? And it's kind of circular logic from there."

"Cyborgs have human brains, don't they?" asked Aang. "The monks taught that they have souls, too. So as long as there's a soul, it's a person."

Sokka sighed. "Listen, I don't know a lot about your religion, but my Islands were evangelized as fuck back in the day, and the soul is a discussion I'm not even going to start. So that's why we've got our nice metrics. Like ZHF."

"You can't put a number on humanity," said Aang, frowning. "How can one person be less human than another? That doesn't make any sense!"

"Yeah, _Sokka_. Explain that to little-old-cyborg-me," challenged Toph with a toothy grin.

"It's _science_ ," protested Sokka, in what was far from his most eloquent argument. The truth was, though, that he'd never had to think about this concretely before. He'd never met an actual cyborg before, and then the first one he did meet turned out to be just as human as Sokka himself, and now here was Toph, toeing the line between human and cyborg just because she'd been born sightless. "It's complicated."

"It's not so hard," said Aang. "Everyone knew this shit in the monastery. We didn't need scientists to tell us if someone was a person or not."

Sokka's argument died on the tip of his tongue because Aang couldn't have said what Sokka thought he'd just said.

"Did you just cuss, Aang?" Toph's tone was delighted. "Hell yeah! World's Greatest Language Teacher, you're looking at her."

Aang managed to look simultaneously confused and guilty. Slowly, he asked: "The word 'shit' doesn't mean what I think it means, does it?"

"Nope," cackled Toph.

Sokka took mercy on the kid and told him what Toph clearly wasn't going to. "It’s yet another word that means poop. Not 'stuff', although we use it that way in slang."

"Shithead," added Toph for good measure.

Further argument was forestalled when Pakku came back into the room. "The software is ready. Try establishing the wired connection now."

"You good with that, Aang?" asked Sokka, approaching with the connector.

"Okay," Aang shrugged, doing his best not to fidget as Sokka hooked it up to one of the FlexSicon chips at the base of his spine.

A spark jumped into the dry air, barely missing Sokka's fingers. He frowned; he'd double-checked the amperage requirements, there shouldn't be a problem…

In another room, a smoke alarm began to blare.

Pakku's eyes widened. "Unplug him now!" he ordered, and Sokka hastened to comply as Pakku rushed out to see to the alarms.

"What the hell is going on?" demanded Toph. "Aang? You okay?"

"Yeah, I'm fine." The boy laughed nervously. "I guess the equipment doesn't like me."

"This makes _no sense_ ," muttered Sokka, looking at the numbers scrolling across the flickering monitor. What was even stranger than the numbers was the way computer seemed to be in trouble. Had the fire alarm come from the room that housed the computing cluster? "These numbers can't be right. Aang, your tech – do you know what it does?"

"Keeps me in one piece, mainly? Protection from the environment, like most biotech, I guess," said Aang. "I never understood the details. But everyone in the monastery had them, once you got strong enough."

"I don't think this protects you from the environment, Aang." Sokka looked him in the eye, serious. "It's designed to protect the environment from you."

Toph bristled at that, ready for a fight, but paused when looked at Aang. Sokka, too, had been watching carefully for his reaction; the boy looked strangely resigned and downcast compared to his usual cheerfulness.

"The fuck does that mean, genius?” demanded Toph, finally. “Aang wouldn't hurt a fly!"

That was true, Sokka thought, quickly running some ballpark estimates. No, Aang wouldn't hurt a fly because the biotech he wore was keeping the force of a hundred suns at bay. More than that, even. It was somewhere in between that and the point where a logarithmic scale became laughably inadequate on the axis approaching unlimited cosmic energy.

Sokka gave in and re-formed his worldview for the second time in so many days, and opened his mouth to speak a sentence that he’d never thought would leave his lips. "Aang — I think you're the Avatar."

**Notes for the Chapter:**

> Hee hee... and the wonderful thing about AUs is that absolutely no one is surprised about this. 
> 
> I hate soulmate AUs (and de-aging/age-swap AUs) with a fiery passion, but I do recognize that having Yue and Katara as the Moon and the Ocean is basically a soulmate AU so... Feel free to roast me for being a hypocrite.


	12. Soul and Romance

"You're saying that Aang is the Avatar," stated Toph, incredulous. "Master of all elements, the person who can operate every single failsafe, famously disappeared when the world needed them the most. The Avatar that Zuko's hunting. That Avatar."

"Yup. That's the one." Sokka didn't feel nearly as flippant as he sounded.

"I never wanted to be the Avatar!" cried Aang.

Toph spun on him faster than a boomerang. "You little turd. You knew?"

"No! I mean, well, not exactly…"

"Explain. Now," demanded Sokka. He'd had a hard enough time accepting that the failsafes existed and the Avatar might be a remote possibility, and that was twelve hours ago. To go from that to standing in the same room as said – and presumably very dead – Avatar was a strain even on Sokka's prodigious mental capacity.

"They were going to tell us, the next day. Who the Avatar was. And there were only eight of us kids the right age at the monastery, so it had to be one of us, but –"

"This is like the Dalai Lama, right?" Toph interrupted, turning to Sokka for clarification. "The Avatar Spirit was believed to be reincarnated into a particular religious sect or something?"

Sokka nodded. Close enough, although who knew exactly how these forgotten customs played out.

Well, Aang, clearly.

"— and everyone kept looking at me, because I'd unlocked my chakras and gotten mastery, but it didn't _have_ to be me. It could have been any of the others, too!”

“Really?” Sokka was skeptical. “Literally anyone could have developed that kind of power? I’d presumed it was a freak of genetic luck. Even in this mutant age.”

“The Avatar’s not a god,” said Aang. “They’re not supposed to be. They’re meant to represent humanity. How could they do that without even being human?”

Sokka bit his lip to keep from commenting on just how much of Earth’s population no longer strictly fit that criterion. 

“You could be the Avatar, if you were chosen,” Aang insisted, and this time Sokka openly laughed. Aang frowned but returned to his previous topic. “Besides, they kept saying that they'd take the Avatar away, for more training, and I didn't want to leave Gyatso. How could I do that to Gyatso?"

Aang's distressed arm-waving was enough to start small wind currents in the stale air of the lab. Sokka had no doubts as to how this conversation would be stopped right there for a therapeutic cry if there had been a sympathetic soul like Katara present. Hell, even Zuko was softer than Sokka and Toph about this stuff, although Sokka could only imagine how the Fire Prince would react to finding out he'd had the Avatar effectively captured all along.

"You ran away, didn't you," said Sokka, blunt.

"Yeah," sighed Aang, hands stilling, miserable. "Everything was going to change. It was all so messed up. The monks kept saying that Fire Lord Sozin was angry enough to destroy the world, that mutually assured destruction was imminent, and that the failsafes had to be used now or never. And it would be the Avatar's job to do that. To re-shape the world, when it… it's not even that broken, is it? In the end?"

Sokka stared, incredulous. "What the fuck makes you think that this world is _okay?_ "

"It's – " Aang went back to playing a one-kid ventilator. "It's not so terrible! There's a lot of ice, yeah, but that helps people stay safe! And it's fast to travel across, and we still have fun together. Everyone I've met so far seems to do okay."

"If you call _surviving_ rather than _living_ okay," Sokka bit out. "You could have stopped all of this from ever even happening. The whole apocalypse. I could be a teenager right now, instead of _halfway through my fucking life expectancy_."

"I – " Aang looked down, tears wetting the corners of his eyes. When he met Sokka's gaze again, his eyes were desperate. "So many people would have died."

"So many people _did_ die!" Sokka was yelling now, and the guards by the door were giving each other cautionary glances. At least he was yelling in Mandarin, so hopefully they just assumed he was pissed off at Aang. Which would be an accurate assessment.

"One person can't re-make the world just because they have the power to!"

"And what if it was the right thing to do? Aang, _that's what the failsafes were for_. Are for. So that if… when… we broke the world, we at least had a shot at putting it back together." Sokka had no idea if the terraforming machines of legend were still operational, but he didn't think he was wrong when he assumed that humanity had missed its shot. As a species, they had a track record of that kind of thing.

"You know what they say. Hindsight's twenty-twenty," quipped the local blind girl, breaking Sokka out of his stare down of the guilty child Avatar. "So what did happen, Aang? It's not just the Avatar who can control a failsafe. They're the only one who can make all of them work in harmony, but there were plenty of other people who could operate the individual ones, right? Couldn't the Earth or Fire failsafe have stopped the bombs? Swallowed them right up in their bunkers or exploded them harmlessly somewhere?"

"I mean, I guess so," Aang sniffled, wiping at his eyes with a palm. "I wasn't around to find out. After I ran away, I got caught in a huge storm. I don't know if it was natural, or if someone was messing with the Ocean or the Air, but the last thing I remember was feeling cold. And then a few weeks ago I woke up on Zuko's ship."

Sokka could believe that much of Aang, at least. But something else was bothering him now. "You know, Toph, for someone born in this century, you sure know a lot about the failsafes."

"What are you trying to say, Snoozles?" Toph challenged, blind eyes narrowed.

"That the game's up," Sokka declared. "Want to tell us why you were really in cryo? _Coincidentally_ at the same facility as Aang?"

"No, I don't. You tell me, Mr. Genius."

"Fine." Two could call each other's bluff, and the picture that had been slowly coalescing in Sokka's mind over the past weeks had suddenly come into focus. "You can operate one of the failsafes, potentially. You've got the elemental connection it takes to understand Earth, at least, given your mutation. And you weren’t the only one with something like that. Every single person who was in hibernation there did too. Darwin was attacked by the Southern Raiders, but they left once they'd gotten what they came for."

Toph kicked at the floor, the scrape of it sounding harsh in the silence. "Shit. How long have you known?"

Sokka shrugged, the movement settling him back into what Katara called his annoying know-it-all persona. "I know you've been hiding something since the beginning, but I wasn't sure until just now."

"You're good," praised Toph, before her expression turned crafty once more. "So do you know about Zuko?"

"What about Zuko?" She'd lost the last bluff, and if Sokka knew one thing about Toph it was that she hated losing. But this was just getting pathetic now.

"Hah. You don't know."

"What he's going to do about the Avatar?" Sokka asked the logical question. "For the record, he did say to me once that he wouldn't drag a kid back to the Fire Lord to be experimented on, but I think it's a stupid idea to tell him about Aang any time soon. Or, you know. Ever."

Toph was still wearing what could only be called a shit-eating grin as she sing-songed: "You have no idea."

That was a challenge if ever Sokka heard one. He picked up a few of the most obscure threads he could find, followed them to their inevitable conclusions, and resisted the urge to slap a palm to his forehead. Of course. "Zuko was genetically engineered to operate the Fire failsafe. Thanks to the Southern Raiders, the Fire Nations have people to operate Earth, Air, Ocean and Moon, and with Zuko – or maybe his sister, his backstory's pretty confusing and also fucked up – they have Fire. Now all they need is the Avatar, and they can make the world in their own image."

"Okay, so that first part was what I was getting at," admitted Toph, tone unsteady. "The rest is just scary depressing. Shit, is that what they're really going for?"

Aang's eyes were wide as small moons when he finally spoke. "We really shouldn't tell Zuko, right? Even if he's my friend?"

Sokka nodded, grim. "Hate to break it to you, Aang, but I'm pretty sure Zuko cares more about his honor than his friends. If he even has any friends," he added as an afterthought.

Toph scoffed. "If anyone's Zuko's friend, buddy, you are."

Take one frigid swim with a guy and people just assumed shit. Sure, they had a good rapport, but that did not a friendship make. "We're not friends."

"Right," said Toph, tone dry. "People don't usually want to bone their friends."

Well, Sokka had a pair of working eyes for one thing, which Toph certainly didn't. Nevertheless, he refused to rise to her bait. "I do not! And anyway, that's neither here nor there."

"I see the way you look at him," cackled Toph.

"There's so much wrong with that statement that I'm not going to dignify it with an answer," replied Sokka, incredulous.

"I'm Blind, not blind," Toph shot back, earning a soft giggle from Aang.

"I get it!" he cried. "The word for 'blind' in Mandarin has only its literal meaning when borrowed into in Creole, while the Creole word is mainly figurative."

"Gold star," said his teacher, generously, patting his hand. "Good to know the Avatar is finally learning to talk like real people."

Aang's grin vanished at that bleak reminder. "I mean… we still don't know for sure that it's me!" He gestured enthusiastically with his hands. Across the room, a sheaf of papers noisily fluttered into a neat stack.

"Uh… about that," started Sokka, staring.

"Hey, Airhead," said Toph. "Guess what _your_ elemental connection is."

"But I don't have a mutat—" Aang cut himself off, finally noticing the papers. He looked down at his hands, then back up. "Oh, shit."

Toph cackled and held up hand for blind high-five. Sokka groaned, feeling a headache forming. What kind spirit story had his life turned into?

Speaking of headaches, he could hear Pakku's footsteps in the hall. "Okay, so we're agreed," he hissed quickly, snapping his fingers to draw the kids’ attention. "We do not fucking tell Zuko."

* * *

As it turned out, it was easy not to tell Zuko because between working with Pakku to find a way to replace Aang's ancient cybernetics and the military leaders constantly hounding Zuko for information, Sokka barely saw him.

He barely even saw Katara; the powers-that-be were intent on keeping their travel group apart, Sokka could tell. A necessary precaution, he supposed, and all in all a small price to pay for not being dead. But although he would never admit it out loud, he missed his sister.

He might even, if pressed, admit to missing Zuko too. But certainly not to Katara.

"You do," she insisted, intent on causing trouble. "It's okay to say it. You two really bonded during our trip. To say nothing of your crazy break-in here. Which I am still upset about, by the way."

"Shut up," Sokka protested, half-heartedly. It was amazing how low his will to argue was when he'd already spent all day doing so with Pakku. Sleep deprivation might have played a small part in it, too. "Anyway, it doesn't make sense to miss someone I'm actively trying to avoid."

Katara snorted, casting a judgmental glance at the way he was draped over the furniture. "You don't have the energy to actively avoid anyone."

Accurate, in a way, since it was how she'd managed to tear him from his work without the promise of delicious meat. Sokka still had a thousand things to do, and that was just for Aang. Toph's state was far less complicated, but she still needed a few adjustments to ensure she'd stay healthy for the next decade.

"Hey. Sokka." Katara's tone was suddenly serious.

"Yeah?"

"I've been thinking."

Sokka groaned. "Stop mooning over Yue." Every time he'd seen Katara in the past few days, she'd been unable to shut up about the princess. 

"I don't _only_ think about Yue," Katara replied, snippily. "Although I thought you'd be grateful that we can count on having at least one ally here."

"We're all your allies," Sokka couldn't resist the double meaning. "But for someone supposed to be training with Master Yugoda, you don't seem _quite_ as interested in winning _her_ … trust."

Katara had the grace to flush slightly at that. "I just feel like Yue and I have this fundamental connection, you know?"

Sokka did not know, but that didn't mean he wanted to constantly hear about it. "Stop flirting with foreign royalty," he ordered.

"You know I'm not gonna fight you for Zuko, bro."

Sisters, what the fuck. "Shut up!" It was the most eloquent thing Sokka could come up with on the spot, having suddenly been assaulted by the memory of Zuko's warm arms around him and steady breaths at his back. "And anyway. Even if I did, hypothetically, like him."

"Hypothetically," mouthed Katara, making air quotes with her fingers.

Sokka couldn't believe they were wasting their precious time talking about such dumb trivia as who liked who. "I'm not stupid," he continued. "I know that Aang's the Avatar and I'm keeping that from him. Because no matter how much I believe he might actually care for the kid and have a, you know, human moral backbone, the man is still an Imperial Tracker. Those protocols of his are no joke. I'm not going to bet on Fire Lord Father-of-the-Year having left his son with even a modicum wiggle room in this capture-the-Avatar arrangement. I'm ninety-nine percent sure Zuko's got a geo-activated kill switch, that's exactly how serious the "come back on your shield or not at all" schtick is. We'll be lucky if we can part ways on good terms before Zuko finds out, and then even luckier if we're dead before he finds out and comes back to kill us all."

"How romantic," was Katara's oh-so-helpful contribution to that. Sokka glared at her. "Listen, I know I don't quite understand the whole killer-robot side of Zuko like you do. But he's kept his word to us. He hasn't harmed us. Nor Aang and Toph, and as far as I know he's made no such promises to them."

"You're making a convincing argument for me to have feelings for him, sister dear."

"I just want you to be as happy as I am," Katara sing-songed, mockingly. "Seriously, though. I do. But I understand that now is not the time."

"Do you?" Sokka wondered, because, well. Her massive crush on Yue.

"Unless you think it could lend you an edge in figuring out exactly why the Fire Nations need the Avatar so much." Katara's tone was sly.

Sokka snorted. "I resent the implication that I need to seduce anyone into giving up their secrets."

To her credit, Katara looked sheepish. "Sorry. Bad joke."

Sokka accepted her apology with a sharp nod. "Besides, as I already said. There's only one reason the Fire Nations want the Avatar."

"See, that's the part that I don't understand," Katara protested. "If they already have people who can use the power of each failsafe, why do they even need the Avatar?"

"I don't know the science behind it," Sokka started.

"Lore, Sokka. Just call it lore."

Sokka ignored her. "But think about it. There's got to be something special about the Avatar that makes it all – come together, for lack of a better way of saying it. Remember what Toph told us? They were waiting for technology to catch up, because every time someone tried to use a failsafe, they'd die."

"Then why didn't the Southern Raiders take everyone from Darwin? I wouldn't put it past the Fire Lord to just go through them one at a time. As horrible as it sounds."

"Maybe technology's caught up."

They were silent for a moment, pondering that sobering thought.

"Then why not keep Zuko at home?" asked Katara. "Why send him to find the Avatar, who no one's seen nor heard of for hundreds of years?"

"Maybe Ozai's already got the child he needs," said Sokka. "Zuko's got a sister. What if she's already proven she can use the failsafe, and survive? Zuko becomes useless to the Fire Lord, and let's face it. He can be a stubborn, outspoken asshole."

"No wonder you like him."

Sokka wondered why Katara kept talking when she knew he'd ignore half her dumb statements. "So why not send him off on a snipe hunt on the off chance that you'll get something supremely useful out of it? Kill two birds with one stone. And anyway, even if Zuko's sister has successfully harnessed the power of the Fire failsafe, that still leaves Earth, Air, Ocean and Moon. Maybe they've got enough bodies to power that up for the number of times that they need, but with the Avatar… well, according to Toph, people didn't die like that when the Avatar was around." 

Katara sighed. "You're right. It makes sense. And it explains why everything fell into legend. No one's successfully used a failsafe in centuries, and they were pretty big secrets to start with. So with no evidence of their existence… here we are."

"Yup," agreed Sokka. "Screwed," he summarized.

Katara made a face at him. "Maybe there's something we're missing. It can't hurt to get Zuko's side of the story. Just try and talk to him anyway. Wait, no. Scratch that. You talk a lot. Try to actually _communicate_ with him."

Sokka groaned, but nodded anyway. He hated it when Katara made sense.

* * *

Unfortunately, an idea making sense didn't make it any easier to execute. Case in point, the ridiculous requirements of the tech required to keep Aang from exploding in a ball of unlimited cosmic energy. It made perfect sense to replace his flex-Si-con chips with their functionalities tattooed under his skin instead of imperfectly embedded in it. It did not make it any easier to figure out a way of keeping Aang's potential under wraps while the thirty-six hours of incredibly detailed 3D printing took place.

Aang, being the altruistic cherub that he was, had suggested staying awake and meditating during the whole process. Sokka, who had at this point been awake for thirty-six hours himself and was nowhere near a zen headspace, immediately nixed this idea. Pakku had thought that putting Aang into temporary cyro-stasis might work, but Sokka had argued that based on previous iceberg-based data, it might have been those same massive energy reserves they were trying to avoid that had kept Aang in stasis the first time. In the end, they'd finally worked out a replacement pattern that had an 85% chance of keeping things successfully under wraps. The new tattoos would be designed to illuminate at any sign of malfunction or unexpected energy release, so they could act as a warning even as they were being installed.

There wasn't much to do while monitoring the procedure, so Sokka spent his shifts tinkering. He'd finished Toph's upgrades two days ago and she'd tested perfectly. He was looking for a distraction more than anything when he came across the prosthetic. Sokka felt himself perk up instantly, mind running through specs and requirements in the background as the foreground was occupied with stupid, meaningless things like how Zuko's expressive face might break from its habitual frown upon seeing it… ugh, so maybe he didn't hate the guy.

Sokka glanced at the clock, then settled rapidly into his new project, willing the minutes until the end of the shift to pass by.

He desperately wanted sleep, although he also wanted to find Zuko.

But first, meat.

* * *

"Hey, buddy," Sokka groaned as he forlornly regarded the bottom of his empty bowl of stew. At least the universe had delivered him this much; a portion of relatively tasty meat, and the very person he needed to talk to.

"Hey, how are you," said Zuko, the pleasantry falling flat with fatigue. He still didn't sound nearly as exhausted as Sokka did, the bastard. "Has Aang been keeping up with his self-study?"

"He'll still be asleep for another day or so while we see if the new cybernetics take."

"Oh."

Time passed in a blurry, achy haze that was at least less cold and lonely now that Zuko was there. "Hey I know it's not sleep but. I've got a proposition for you," Sokka came back to himself eventually, just in time to internally facepalm at his phrasing. Fortunately, Zuko didn't seem to notice, just cocking his one eyebrow. "I know it's not your father's love and affection—" and Katara was right, Sokka had no filter when he was this tired “– but do you want a new eyeball?"

Zuko's eyes were both as wide as they could go at this suggestion. Before he could properly respond, Sokka unceremoniously pulled the case out of his bag and plopped it on the table, popping open the lid as he did so. A crystal-blue iris stared up at both of them.

Zuko stared back at it for a moment, then looked away.

"You don't have to." Sokka started babbling to break the tension. It was a stupid idea, he'd known it was stupid, but he'd felt guilty and he knew it was nothing compared to a proper Tracker eye, either in capabilities or what it symbolized, so he'd done it even if he expected to be turned down anyway. It was all cool, though; Sokka would just brush it off with some snarky remark about how it wasn't his fault that Zuko couldn't adult and go to a cybermech once every three years –

"Yes," interrupted Zuko.

"What?" Sokka blinked.

"I –" Zuko looked back at Sokka now. A myriad of emotion was written on his face; resignation, gratitude, the beginnings of hope. "Please," he added, and that was all that needed to be said.

* * *

Zuko wanted him there, for the surgery. Sokka would really rather not. Katara was the one with an actual interest in medical goings-on, and who was far less squeamish when it came to blood. Sokka had tried, though, and made it as far as the buzz cut and anesthetic before he’d bowed out of the operating room.

When they wiped away the last of the fluids and Zuko opened his eyes, it was unexpectedly beautiful.

"Hey," Sokka said, admiring his handiwork, watching the bright blue iris slowly focus. _I did that_ , he thought, with the characteristic pride that came with a completion of a new project. But different from that, a new thought: _I did this. For him._

Leaning back from his inspection, he was momentarily taken aback by mismatched colors. An eye was just an eye, after all, and for some reason he wasn't expecting that it would be anything other than fiery gold, now that it was Zuko's.

"You can change the color," Sokka explained, hastily, eyes darting back and forth between blue and gold.

"I don't mind." Voice still hazy from drugs, Zuko nevertheless sounded… happy. "I can see. Just like… just like I remember. Thank you, Sokka."

"You're welcome." Something in Sokka thrilled to hear those words, and he busied himself with handing the other man a mirror. "You could, though. So it's more like how the real one was."

Zuko only glanced at the mirror, before looking back at Sokka. "I don't mind," he repeated. "I like it. It reminds me of you."

Sokka's lungs malfunctioned for a hot second, and his traitorous brain considered that Katara and Toph might have had the tiniest fraction of a point with their assessments of how he felt about Zuko. Thankfully the next thing that happened was that guilt hit him like a hammer, and damn it, Katara was right. Sokka couldn't continue lying to the guy, if he wanted to keep what they had, much less progress it. And what was even more dangerous was that he no longer wanted to.

Sokka pasted on what he hoped wasn't an overly awkward smile, accompanied by two thumbs up, and against his far better judgement, resolved to actually talk to Zuko about the Avatar.

* * *

It took another round of sleep-deprivation and a new science project for Sokka to work up the nerve. But there wasn't really a better time and place than this, in the dead of night on Zuko's ship, parked now in a concealing snowbank on high ground a few kilometers outside of the main habitation.

Sokka had suggested using the ship to extend the baseline of their radio array in order to reconstruct intercepted transmissions on a finer scale. A few more tweaks and he'd have the calibration just so; then there would be nothing left to do but… talk. Ugh.

"Time to test," Sokka said finally, putting down the tablet. "We'll try for a quick image with the infrared interferometer first. Monitor the screen for me?"

Zuko nodded, and took the pilot's seat while Sokka squeezed into the navigations corner, made even more cramped now by additional equipment.

"It shouldn't look like much," explained Sokka, deeming the integration time sufficient and starting the image reconstruction algorithm while he went through the instrument diagnostics. 

"Got it!" he heard from the cockpit, and then a weird strangled sound.

"Zuko?" Sokka looked up from the monitor, curious. "Everything okay?"

"Uhhh…"

That was enough to catapult Sokka the two-and-a-half meters to the cockpit. "What is it?"

Zuko looked like he'd seen a ghost. Which, okay, was actually a strong possibility, their dynamic range wasn't great and ghost images were not infrequent when it came to Fourier imaging. "If the point-spread function is visible, it's not real—"

"It's real." Zuko cut him off abruptly, and leaned to the side so Sokka could get a better view over his shoulder.

"What is that?" he wondered, unease building in his mind the more he looked at it. It was a sigil of some kind, but without any context Sokka was at a loss.

"It's the royal family's symbol." Zuko expanded the image field of view, revealing a tight cluster of parked battle cruisers. "It's Azula. My sister."

**Notes for the Chapter:**

> Some inside jokes in that last section regarding radio telescope image reconstruction... and then blatant lies, as you'd never get an actual image of something like a logo from such a telescope.
> 
> I'm never not going to make moon puns about Yue...
> 
> The true pairing here, as you can clearly tell, is Sokka x meat
> 
> I commissioned a drawing of Aang with his new tattoos/cybernetics, so check back in a few weeks to see it! I'm certain it will be fantastic :) Or follow my tumblr @d-naggeluide
> 
> Update 30.10.20 - for those Yue x Katara shippers out there, check out a missing scene that happens in between the previous chapter and this one! _Gravity_ , linked in the end notes of this work.


	13. Condolences to good

The expression on Zuko's face didn't exactly spell family reunion fun times, Sokka noted. He was no stranger to occasionally panicking when Katara entered a room, but it was nothing compared to Zuko's frantic body language right now.

"We need to evacuate. Get everyone out," hissed Zuko, voice low to avoid alerting his watchdogs, who were playing cards in the kitchen. "There's no winning this if Azula is involved."

"Easy there, buddy." Sokka didn't quite have the space necessary for calming hand gestures in the cramped cockpit, but he tried his best. "Listen, I know sisters can be a lot, but let's not jump to dire prophecies of doom and gloom. Also, who are you and what have you done with 'never give up without a fight' Zuko?"

"You don't understand!" Zuko was angry now, go figure. "It's Azula. She's got the full power of the Fire Nations military behind her, she's a genius, and she's ruthless. She's me if I actually wanted you dead. Passionately and personally."

That was a less-than-pleasant thought, but of course Sokka's stupid lizard brain had attached an entirely different scenario to that last phrase and made his heart hop a little. He scolded it severely, and switched over to the part of his brain that was already planning. "Okay, so we've got a sister problem."

Step One, admit that there's a problem. Sokka and Katara were experts at avoiding Step One, but hopefully Zuko and his sister were different.

Step Two…

"I'm going to need more information. Tell me everything."

* * *

Everything – even the abridged version – turned out to be extremely fucked up, to make use of a technical term.

“She’s crazy and she’s got to go down,” IROH summed up.

“Uncle, _we’ve talked about this_ ,” hissed Zuko. “It’s not that simple! Just because we might not understand her reasons for doing things doesn’t mean that she doesn’t have them. Azula never does _anything_ without a reason. Which is to our advantage in this situation; she knows she hasn’t got all the information, and I know she’ll listen to me if I tell her. This attack is self-destructive to the Fire Nations’ interests, she’ll see that right away!”

"You think that despite all… that," Sokka made a hand-wavy gesture that failed to encompass the insane amount of drama that was the Fire Nations royal family, "Talking to her can make a difference?” Sokka could really see where IROH was coming from on this point. “You, her practically estranged --"

"Banished. 'Estranged' implies choice."

"— banished older brother, whom she hates, since your parents – "

"Just the Fire Lord, leave my mother out of it."

"— parent pitted you against each other from birth in order to find out which one was best suited to controlling the Fire failsafe, with the full intention of throwing away the one who couldn't. Uh, Earth to Fire Lord Ozai? What about both?"

Zuko couldn't help a bitter snort of laughter at that, but he was sober again in an instant. "Azula won't throw away an advantage. She'll see me as a someone she can use."

"Makes sense, if we want to give her more advantages." Sokka couldn't have laid on the sarcasm thicker.

… Actually, this was Zuko he was talking to. He probably should have tried to lay it on thicker.

"It might be our only chance."

And that broke through Sokka's joking façade like a battering ram of cold, hard, truth. As much as Sokka hated to admit it, Zuko might be right about that. Even if they didn't have the full story of Baikonur’s military capabilities, there was a high probability that compared to the Fire Nations army camped scant kilometers away, they were both outgunned and outnumbered.

"What does she even want with this place? To destroy the failsafe?" There's no way she could know about Aang, Sokka told himself. Even Zuko didn't know about Aang.

"It's the only military target. But that can't be the whole story." Zuko frowned, whispering urgently now. "Azula is a precision weapon. She doesn't need an army, and yet she has one. Why?"

"There might be someone here who can operate the failsafe," Sokka guessed. "The army would be… insurance against catastrophic retaliation."

Zuko nodded. "I've been thinking about that. But I haven't found any indication that such a person exists. And it's not a large settlement."

Sokka found himself forced to agree. "Unless you listen to Katara go on about her crush," he joked. "You'd think Yue had lit the moon and hung the stars just for her."

"If Yue's got a spiritual connection to the Moon, though, that would mean Katara's connected with the Ocean. You can't have one without the other, with Water." Zuko looked far too invested in this teenaged love story than Sokka wanted to consider.

"Can we please stop talking about my little sister's love life, it's highly disturbing," Sokka complained. "And I grew up with Katara. I would know if she's the physical embodiment of the Ocean."

"Either way," Zuko shrugged it off. "This complicates things. As much of a loss as the failsafe would be, there's no way Baikonur will evacuate if one of their own even has the potential to use it one day. They'll have to fight, and then they'll lose. I have no choice but to face Azula, and try to make her see that the destruction of the failsafe helps no one."

"And if she rightly accuses you of trading military secrets to the other side?"

"I'm not a traitor!" protested Zuko. "Would a traitor risk their life to tell their nation's military leaders that they're about to make a huge mistake?"

"Fine, I get it! Look, that was a poor word choice." Sokka came dangerously close to an apology, but got caught up on something else Zuko had said before he got that far. "Wait, who said anything about risking lives?" 

"You don't have to come with me, this time."

"What. The fuck," said Sokka, with feeling.

"There's no better time to go than now," said Zuko, earnest. "We have no idea when they plan to attack, but Azula has never been one for hesitation. We're physically close right now, and you can cover for me while I'm gone."

Sokka stared, hating his brain for almost instantly handing him a checklist of things to do before their inevitable departure into the mouth of the beast. "It's amazing you haven't managed to get yourself killed yet," he settled for, fingers already flying over the console keyboard, preparing data to send.

"Nobody's going to die today," shot back Zuko.

"There's like two hours left in today, so that's a pretty low bar."

In the end, it only took twenty minutes to alert Yugoda that the Fire Nations were coming, say that Zuko and he were on their way back, and sneak out on the sleds they came on before their gambling guards were relayed their orders. IROH had gone on about secrets of the house blend in the meantime, serving as a good distraction.

“And remember!” the AI insisted before they disconnected from the local communications. “You must never give into despair. Allow yourself to slip down that road, and you surrender to your lowest instincts.”

Sokka gratefully gunned his sled out of range of IROH’s lecture, sliding out on the ice ahead of Zuko, who he could see nodding along with the remainder of the AI’s fake wisdom, and pulling his hood tighter about his ears.

Sokka knew what happened when he let his instincts take over. Zuko’s, at least, seemed slightly more reasonable; running away from your crazy little sister was far more logical than running toward your enemy and hijacking his ship. But Sokka wasn’t going to let it come to that. This whole side-quest was one of reason; instincts, familial or otherwise, had no place here. Zuko was lucky to have Sokka along to guide him.

"Where would you be without me, honestly," Sokka grumbled into the headset as the ice slid by beneath them.

"Sometimes I'm not sure." Zuko's voice was pensive over the communicator, even if the harsh line of his body on the sled didn't change.

"Probably still half-blind and shaking down old people in tiny villages looking for the Avatar, am I right?"

Sokka imagined Zuko's wry smile in his reply. "Something like that, yeah. Thanks for coming. Again. You didn't have to."

"Someone's got to watch your back. Lord knows you won't," said Sokka. The distortion of the communicator would be enough to mask any trace of warmth in his voice, he was certain. "Besides, don't thank me yet. We still have to get into the place."

* * *

"I can't believe you can just walk on board," hissed Sokka, ducking behind a pillar. Who even had pillars in their military vessels? Another point in support of his theatre-reject theory.

"I guess they never bothered deleting me from the system." Zuko shrugged, peeked around a corner, and beckoned for Sokka to follow. "I've got the right DNA too."

Ordinarily the kill switch would do the job of the lax security, Sokka thought sourly, so why bother. Fire Nations logic never failed to amaze him. That wasn't to say it didn't have its benefits. Why else would they currently be strolling unhindered down the corridors of the Fire Princess's flagship?

In front of him, Zuko drew to an abrupt halt, holding up a finger. Then he disappeared.

Standing exposed in the corridor, Sokka cursed silently.

"Get up here!" Sokka barely heard Zuko's low voice, and looked up into the deep red shadows. For once he could say that Zuko had made the right choice of color palette, at least. The pose he'd taken, however, was rather outlandish. Sokka had no idea how the man had managed to wedge himself in between the ceiling, wall, and what looked like some kind of pipe or cable guide. Much less how to get there himself.

"Hurry!"

Necessity was the mother of invention, Sokka had read once. It was not however, the mother of flexibility, and Sokka definitely relied more than he would have liked on Zuko's helping hand to un-gracefully haul himself above eye-level. From that level, he could see a narrow, shadowed catwalk meandering behind wall and ceiling panels, and they quickly made their way along it, deeper into the ship.

"Where are we…" Sokka cut himself off as he heard the first rumble of voices. He monitored every footfall as they crept closer, unable to tell past the thunderous beating of his heart if they stayed silent or not.

He recognized one of the voices, from its sycophantic self-adoration.

"This will truly be one for the history books, Princess Azula. The Fire Nations will, for generations, tell stories about the great Zhao, who darkened the moon. They will call me Zhao the Conqueror, Zhao the Moonslayer, Zhao the Invincible!"

"History is not always kind to its subjects, Admiral Zhao." The woman's voice was smooth and self-assured, cutting brutally through the boasting. Sokka knew at once that this was Azula, and that Zuko had been right to fear her. "And it has been generous to men like you for far too long."

"Men like me are the heroes of such triumphant victories, Princess. Have I not delivered to you the hidden location of the Moon failsafe, along with the key to its destruction? You may captain this flagship, but this is my victory."

"Victory has not yet been accomplished. You get ahead of yourself. And even if the control interface and machinery here are destroyed, there still remains the problem of those devices on the Moon itself."

"Princess Azula." The condescension and creepiness that Sokka and Zuko knew too well were back. "I am an honorable man." At that, Sokka elbowed Zuko softly to share an exaggerated eye roll. Zuko didn’t bother hiding his smirk.

"Would I have asked the Fire Lord for military resources if I didn't have the information needed to cripple this failsafe permanently? It is true that we can do no harm to the great gravitation machines buried in the lunar surface. But their activation requires not only an operator but also a method of relaying those commands. And to transmit such a volume of data over the time required is something bordering on the impossible, ever since satellites started falling from the sky. However, in my travels, I have uncovered the secret!”

Although Sokka highly doubted Zhao’s ability to elaborate clearly on anything technical, he found himself leaning forward to hear better.

“The workings of the lunar engines are beholden to their earthly avatar. However, the massive amount of information needed to operate them is enough to overwhelm even the most advanced brain, human or cyborg. A special machine sifts through the signals, interpreting them for their user! In ancient times, it was called a correlator.”

“Such as the instrument that allows the Avatar to simultaneously coordinate the five failsafes?” Azula asked, sounding interested despite herself.

“Much the same, as I understand, only the Moon’s must operate over the vast distances of space. Therefore its dependencies are threefold: the user, the communications network, and the correlator. The user we could easily neutralize, were we to slay the entire settlement.”

Sokka felt a chill run down his spine at the callous statement. He’d been right to warn Baikonur; no matter how unlikely it was that they would flee, he couldn’t help but wish it anyway.

Azula sniffed in dismissal. “A brilliant way to set back the Fire Lord’s ambitions until well past his lifetime, should we be reduced to acquiring their accumulated knowledge from nothing.”

“Indeed.” Zhao’s agreement hid a note of reluctance. “Destroying the communications network would be a vast military undertaking, as the receivers are spread across the planet, often in unhospitable environs. The correlator, however, is vulnerable. And I have uncovered a way to trace its energies to its very center! A single strike shall darken the Moon, and the honor of the Fire Nations and their Lord will shine even brighter!”

"Impressive," purred the princess. Zhao soaked up the apparent praise, until her voice turned hard and cold. "But you've made a fatal mistake. The secret of the correlator you may have discovered on your own, but knowledge of this place – that, you stole from one of mine."

Zhao recovered quickly, with a derisive scoff. “The Banished Prince? He's less than nothing, a traitor! Divulging that information was the most useful thing he could have done for his country.”

“A traitor he may be, but he is still my brother. And that is far more than you will ever be, Admiral though you style yourself.”

Beside Sokka, Zuko looked torn between annoyance and pride – a feeling that Sokka knew only too well.

“I can see your whole history in your eyes,” Azula continued, and well, that was something Katara couldn’t do. “You were born with nothing, so you've had to scheme, and flatter, and murder your way to power. But true power, the divine right to rule, is something you're born with.”

Sokka would be relishing the look of uncertainty on Zhao’s face that was growing larger than the ugly sideburns adorning it, were he not dealing with his own slowly dawning terror.

“The fact is, my father doesn't know which one of us is going to be sailing home in victory, and which one is going to be dead,” Azula declared, as she slowly made her way into view, up to a small dais, where an elegant wooden throne commanded the room. “But I know, and you know.” She ascended, and sat down, crossing her legs. One perfect dark eyebrow canted upwards. “Well?”

Sokka held back a full-body shudder. This was what they were up against? Zuko’s earlier panic suddenly made a lot more sense.

“You've beaten me at my own game.” Zhao sounded bitter in defeat.

Now it was Azula’s turn to scoff. “Don't flatter yourself! You were never even a player.”

* * *

Sokka needed an instant to collect himself, but that was all it took. This was no game, after all. He wouldn’t let himself get played.

"Do you know where it is? The correlator?" Sokka whispered urgently, plans and contingencies already spinning around in his head.

Zuko shook his head.

"Zhao said follow its energy, that has to mean something electrical, if I get back to the ship I can probably –” Sokka broke off his thoughts as he realized: “Yue will know." And to find Yue, they would have to find Katara, and Sokka had always had a sixth sense for where his sister was. There was still time, they could salvage this before anyone got hurt beyond repair…

"You'll have to draw them away," Zuko whispered back. "Azula can't go through with this, it's madness to cripple the failsafe like that, she must have something else planned entirely. But Zhao's unpredictable, in his rage. Keep him away, at all costs!"

Sokka glanced down, to where Zhao was fuming. Quietly, for now, but if he knew anything of the man it would quickly turn to violence.

When he looked back up, Zuko had turned to go. 

"What are you doing?" Sokka hissed, laying a hand on Zuko's arm. He knew what was coming, but… they could still just leave. Turn back, together.

"I have to do this," Zuko reminded him, blue eye stern and serious. "I won't ask you to follow me."

He knew that Sokka couldn't. Sokka swallowed past a lump in his throat, and nodded. Damn, but sometimes he hated being a realist.

"You did good," he choked out.

Zuko's gold eye widened in surprise.

"By us," Sokka clarified. "Me and Katara, Toph and Aang. You kept your word to us. Even after we stopped travelling together."

"I had no choice." Zuko’s small, lopsided smile made it clear he wasn’t just talking about the programming. "And maybe… maybe it's not over yet."

"Yeah." It came out sounding like a lie, but that was hope sometimes. Against his own will, Sokka found himself asking, hoping: "You'll come back, right?"

Zuko’s expression was pensive. "This isn't goodbye. I promise."

Sokka watched as Zuko dropped light-footed into the shadows. He frowned at his hand, involuntarily outstretched as if to hold him back.

Well, fuck. Torn, Sokka backed deeper in to his own concealing shadows, and watched as Zuko approached his sister.

* * *

"Azula." Zuko's raspy voice interrupted Zhao's simpering protests as soldiers not-so-subtly escorted the disgraced Admiral away.

"You!" Zhao spun, snarling, only to be yanked back around and away by his handlers. Zuko and Azula both ignored him entirely, eyes locked on one another.

Sokka, too, was trapped like potential energy in their electrifying gazes, and had to remind himself to follow his own objective. But Zhao was going nowhere fast, so surely he could linger just a little bit longer…

"Well, well, if it isn't little Zuzu," cooed Azula. Sokka choked back a snort at the incongruity of the dramatic use of the childhood nickname. He supposed he should be grateful that the siblings hadn’t slipped back into their own dialect yet. "I was wondering when you'd come calling. Thought you'd snoop around a little bit first? I'm insulted. You know I have nothing to hide."

"I'm not here for a family reunion."

Azula clicked her tongue. "Would it kill you to be grateful even for an instant? I was the one who kept Dad from taking you out of the system, you know. He wanted all records of you struck from the face of the earth, after your failure."

"Failure?” The habitual growl in Zuko’s voice was more pronounced now. “Tell that to the people whose lives I saved. Tell that to their families."

“You had the power, and you failed to do what needed to be done,” Azula declared. “I don't see what the issue is. I'd have to agree with Dad's assessment – a weakness of character. A lack of honor.”

Predictably, Zuko bristled at that. “Perhaps it was a weakness, but since then I've learned that it was still the right thing to do.”

Sokka wasn’t sure what exactly they were talking about, but Azula seemed to find it funny. She made a short, sharp sound that was probably supposed to simulate a laugh. “You didn’t even have the decency to die in the process like Uncle did.”

“I lost my eye because of that!” shouted Zuko. Sokka had to admire how well Azula could push his buttons, and did a grim re-assessment of how likely Zuko was to get her to agree to anything, much less change her mind.

“And you've moved on oh-so-quickly, I see,” Azula mocked. “Did Zhao give that to you in return for your data?”

“You know he would never pay for anything he thought he could just _take_.” Zuko visibly gathered himself, pushing past to get to the reason he was there. “And you know what he is. This is madness, Azula. Destroying the Moon failsafe will only hurt the Fire Nations as well.”

“Oh, I agree, brother mine,” said Azula. “Destruction was never the goal. This isn't an army for conquest. It's an army for colonization. We'll raze Baikonur to the ground and take the failsafe for ourselves. Then we’ll be one step closer to absolute victory. Just think of it, Zuko! A new world. A safe world.”

Sokka didn’t see how razing Baikonur counted as _not destruction_ , but even so, the way Azula framed her arguments was extremely compelling. Wasn’t that what they all wanted after all? A better world? Of course, there had to be a catch.

“With Fire Lord Ozai as supreme ruler of all, and yourself the true power behind the puppet King?” asked Zuko, bitterly.

“It's not too late for you, Zuko,” Azula plied. “You can still redeem yourself. I need you, Zuko.”

She stood up from the throne, slowly descending the steps of the dais, like a cat stalking her prey. “I've plotted every move of this day, this glorious day in Fire Nations history, and the only way we win is together. At the end of this day, you will have your honor back. You will be avenged for Zhao’s crime against you, given the glory he would claim for himself. You will have Father's love. You will have everything you want.”

Sokka was as frozen in her thrall as Zuko was; he watched wide-eyed as she reached up to Zuko’s neck, dim lights glinting off of something in her hand.

“You deserve this. If it weren't for you, we wouldn't even be here, after all.” A barely-audible beep sounded as cybernetics in her hand activated, and Zuko’s eyes widened as his mouth parted in shock.

“You are free to choose,” Azula said, softly.

Sokka understood immediately, and while a part of him was glad, another part was sick to his stomach. She’d de-activated the kill switch; she’d meant every word she’d said.

Shaking slightly, Sokka picked himself up from where he’d been crouched on the catwalk, and silently made his way out. He’d put off following Zhao for too long, caught up in the siblings’ drama; it was time to go.

Sokka brutally squashed down the corner of his mind that was berating him for running away. It was true, in a way. And yet he still found he couldn’t bear to watch anymore – because what would happen if Zuko didn’t choose him?

**Notes for the Chapter:**

> Were you expecting Siege of the North? Ha ha, welcome to Crossroads of Destiny. Grand finale coming tomorrow...
> 
> I am, apparently, way more of an Azula stan than a Zuko stan, because I absolutely hate the fandom's hobby of labeling and diagnosing her (Zuko too) when all those labels and boxes become irrelevant once you enter a world that's even a touch crueler than canon. Anyway, I really enjoyed letting her completely humiliate Zhao.


	14. So long to devotion

A spray of ice shot crystals into the pre-dawn air as the sled's runner caught on a bump. Sokka cursed and gripped tighter with hands and thighs, keeping himself bound to the seat instead of flying all over the place like his thoughts were. He squinted again through the googles, leaving them on night mode for now, spotted the tracks, and re-adjusted his course.

Trying once again to silence the klaxons that were wailing _don't trust her, choose us, please choose me_ , Sokka concentrated on the task at hand: following the sled tracks he'd found leading away from Zhao's ship – towards the correlator. That could be the only destination the disgraced admiral and his party had in mind.

Sokka knew he had to get there before Zhao could damage it irreparably. And then he had to warn the others. Why hadn't they brought the long-range radios? The risk of the signals being intercepted would be worth it, to cost the Fire Nations the element of surprise.

It was supposed to be quick, that was why. Reconnaissance. In and out. _Both_ of them, out.

Looking back, Sokka knew that he'd just wanted to believe that he had a stronger hold over Zuko than his own sister did. That Sokka was on the side of reason, truth, and moral good, absolutes that went deeper than blood ties. If he called it what it was, selfishness and desire, was he any better of a choice than Azula?

Doubt was one thing he couldn’t afford right now, so Sokka comforted himself with the numbers, focusing his mind on the task ahead.

Catch up to Zhao, preferably before the mad admiral and his force of a dozen armed-to-the-teeth androids could destroy the failsafe. Find his sister, find Yue, get them both far away from here. Evacuate the rest of Baikonur, scrub the databases so it would take Azula a lifetime to even get the failsafe to turn on.

As for Zuko…

Zuko would come through for them. After all, he’d _promised_. 

* * *

Sokka had grown up on the ice; he'd been driving snowmobiles for as long as he could walk. And he wasn't a monster of a man weighed down by countless mods. Still, by the time he got there, it was almost too late.

Worse, Zhao wasn't the first one there.

Facing the man and his cadre across a circular walkway were Katara, Yue, Aang and Toph. 

Sokka spared a quick glance for his surrounding environment. For some reason, this is not what he'd expected the computational heart of a terraforming engine to look like. Like most structures, it was under a dome of ice; he’d managed to stumble in onto the walkway perfectly between the two opposing parties.

It was an observation deck of sorts, because of course it was; below, far, far below, was a still pool, glowing softly as complex calculations ran through its fluids like thoughts through a mind. Sokka had heard of such artificial brains, but he’d pictured the ebony racks of a data center, not something so… beautiful.

Not that the usual hardware wasn’t there; the flickers of light from the pool (it wasn’t a pool, Sokka knew this, but for once the technical jargon seemed insufficient to describe it) threw reflections off the dark stacks of electronics that reached almost to the walkway. Glancing upwards, Sokka saw carefully covered and retracted panels, and he knew in an instant that no matter their age, they could be extended in an instant, fitting into a perfect parabolic surface with a smoothness of mere microns.

It was the main radio dish at the heart of the deep-space communications network, then, with the correlator below ready to parse the intricate signals at the command of its user.

"Sokka!" exclaimed Katara, relief evident in her voice. "We came here the moment we got your message. Yue said – well, we'll explain everything later." Her eyes narrowed as she glared at Zhao. "Right now, we have a pest problem."

"Do you really think you can match me, Zhao the Moonslayer, little gi --"

An iceberg swallowed up his words and Zhao and his killer androids with it.

"Yes," answered Katara, calmly.

Sokka let out a breath he hadn't known he'd been holding, and sprinted over to join his friends. "What's the status of the evacuation?" he demanded, grabbing his sister for a brief hug. Wow, he really must have been stressed. "Where's Yugoda and her forces? They’ll want everything intact, which will slow things down, but in the worst case she'll need to prepare to slash-and-burn behind a retreat –"

"Sokka!" Katara shouted an interruption. "We're not –"

"— fucking running!" interrupted Toph, stamping her feet. The ground trembled below her. "So you'd better be ready to kick Fire Nations butt!"

"What?!" Sokka knew his tone was approaching a screech even more than Toph's had, but he could not believe this. He'd warned them. He'd given them a plan, and this was what he got in return?

Katara read his expression and hurried to intervene. "You're missing information! I promise, Sokka _I promise_ we considered everything you told us. But they're not going to leave. This is their home, Sokka! There's no other place, no other option! And Yue –"

Sokka whirled on the princess. "It's you, isn't it?” The missing piece. “You're the one who can work this thing." He gestured around them.

"Yes, Sokka. It's my duty to protect this place. To do whatever it takes to ensure that the Moon never abandons its mother Earth. Including turning the great engines should the need arise." Her tone was solemn. She meant every heavy word.

Sokka drew in a ragged breath; he should have seen it earlier, it was so simple and had been right there all along. Perhaps he’d been jealous of his sister and Yue, their joined hands and unspoken connection; perhaps he’d simply not wanted to believe that his _sister_ , bratty little Katara, was, by extension, powerful enough to move the Ocean.

Well, he’d gladly accept it if it meant Zhao was currently a frozen pillar, but how would ice measure up against fire?

"The best thing you can do for your people is to get them out of here,” Sokka urged. “The person you're up against – the Fire Princess – she's ruthless. Defeat is not an option for her.”

Azula hadn’t even needed to touch Zhao to eliminate him. If she wanted the Moon, she would have it, and Sokka and Katara had a new priority: salvage what they could and get Yue far, far away from here.

“Defeat is not an option for me, either,” countered Yue, softly. At her side, Katara stood tall.

Sokka let out a noise of frustration, dragging his fingers through his hair and contemplating the futility of getting these women to do _anything_ they didn’t want to.

“Where’s Prince Sparkle Fingers?” Toph asked into the silence.

“Trying to talk his sister out of world domination,” Sokka replied, hoping he was still telling the truth.

Katara winced. “Oh, good luck with that.”

Sokka flashed her the finger. “Don’t get any ideas, _sister_.”

“As if I would ever –”

A loud crash and hiss interrupted her indignant protest. Steam rushed over them, and Sokka put out an arm to grab Toph; if anyone wouldn’t have a problem leading him to a better angle, it would be her.

“You rise with the Moon,” came Zhao’s gravelly voice, forced over the lingering ice in his throat. “I rise with the Sun.”

Again with the dramatics. Sokka let go of Toph and took a wild guess at Zhao’s location before sending Boomerang there.

He was rewarded with a solid-sounding thunk, because Sokka’s wild guesses were other people’s sure things. Then electricity crackled and a ray of new-risen sunlight cut through the steam to show Zhao, whip in hand and blood-red eye fixed directly on Yue.

“Yue!” Sokka and Katara screamed together. Sokka hoped that the lower register of his voice conveyed less _I love you_ and more _If you’re going to do something with those fancy Moon powers, do it now._

The Princess only spared them a glance before running to the edge of the railing and leaping over.

“YUE!”

They were all yelling now, even Toph, and Katara only beat Sokka to the railing by a fraction of a second, her wrist firmly caught in his hand to keep her from following Yue in her fall.

It took no more than four seconds, but the fall seemed to last far longer, Yue’s clothing whipping up around her as white hair streamed behind. Impossibly, she alighted almost gently in the swirling pool below – a glance at Aang showed him in some complicated stance that Sokka guessed was responsible – until she was almost up to her waist in the fluid.

She stretched her arms wide, and fibers climbed up her torso to spread out along her arms and twine up her face, their tips flashing with tiny lights as they ended tangled with her hair.

Yue looked up, and opened her eyes.

Power flashed, the pool alight in a swirling galaxy for a moment before fading and taking most of the light in the room with it, save for the lone ray of sun, which itself was slowly being shut out as smooth panels shook, moved, and slotted rapidly into place with soft clicks.

Lightning crackled, blue sparks flying in a shade that paled in comparison to Yue’s electric eyes, and shocked them all into motion.

Zhao had jumped the railing, cybernetic hand screeching through databanks as he used it and the wild lash of his whip to slow his descent.

“NO!” screamed Katara, and Sokka let go of her immediately, trusting her to do what needed to be done. Aang was doing something that sent a localized tornado to harry Zhao, and Toph…

Fuck. Sokka leapt and grabbed her hand, pointing her finger at Zhao and calling out the distance. “Twelve meters, fall speed approximately one meter per second!”

Toph’s chunks of concrete almost hit their target this time, but were scattered at the last moment by a combination of Aang’s wind and the thrashes of Zhao’s whip.

“Dammit!” Sokka cursed. Where was his heat-seeking spear when he needed it? “Rocks are doing more harm than good right now.”

The glow surrounding Yue had dimmed somewhat when the concrete slammed into a rack of electronics.

“God, why can’t I bend fucking metal?” Toph complained, stomping her foot angrily. “I’d crush that asshole’s face in with his own stupid skull helmet.”

Sokka returned the sentiment, but there was nothing he could do about it right now.

There was nothing he could do, and he hated that, as much as or even more than Toph. Katara was riding down towards Yue on a column of ice, and Aang was literally hovering (since when could he do _that?)_ while he gave Zhao hell from above. And Sokka was out of weapons, save for one blind, bloodthirsty twelve-year-old who was also out of her element.

“Time to go _fishing_ ,” Zhao growled, twisting away from Aang’s whirlwind and splashing down into the pool.

He raised his whip.

Katara screamed, a flurry of icicles burying themselves in Zhao’s armored back as she leapt off her pillar, hands outstretched, desperate.

Above Sokka, the last panel of the radio dish clicked softly into place, sending their little world into black, white, and blue.

A great engine roared to life, the fibers around Yue aglow and pulsing with energy.

Then the whip crashed down, cutting off all sound except for Katara’s screaming.

“What happened?” whispered Toph, clutching at Sokka’s hand. “What’s going on?!”

“I…” Sokka swallowed. He couldn’t say for sure.

The whole area was almost completely dark now, only a soft glow left in the pool.

It was tinged red.

“It is my destiny, to destroy the Moon and Baikonur,” Zhao intoned, brief sparks from his weapon illuminating Katara, hunched protectively over Yue’s limp form.

“Destroying the Moon won't hurt just Baikonur,” shouted Aang, distressed. “It will hurt everyone, including you! Without the Moon, everything will fall out of balance. You have no idea what kind of chaos that would unleash on the world!”

“There is no hope now.” Yue’s whisper floated up from the darkening pool below, backed by Katara’s sobs. “It’s over.”

“No,” sobbed Katara. “Yue, no, no, it’s not, it can’t be…”

The glow that had surrounded Yue persisted, Sokka noted distantly, although she and Katara were so wrapped up in one another now that it almost looked like it came from the water in Katara’s hands rather than the fiber optics from the correlator. And as long as there was power, there was still a chance…

Sunlight burst to life once more, throwing the gruesome scene into stark relief for an instant before a shadow swept over it, to be dispelled a second later with fire.

“Zhao!” shouted Zuko, plummeting uncaring into the abyss. “Whatever you do to that woman, I will return on you tenfold!”

Well, all the machinery here was officially toast, what with fire, ice, and electricity set to duke it out below.

“Come on, Toph, let’s break this place apart!” Sokka ignored the leap of his heart and jumped into action, herding Toph towards where he’d spotted a maintenance shaft. It would most likely be concrete, and then together with Katara's ice they could trap Zhao in a hard pointy sandwich.

"Fuck," swore Toph, the instant her feet touched the framework of the shaft. She continued her profanity for a frantic second before turning on Sokka. "Who the fuck called the army?!"

Shit. Sokka had the sinking feeling that he knew who, and the logical capacity to confirm it.

"Get us topside, now!"

He'd wait to see it before he believed it.

Toph summoned a concrete pillar to punch through the elevator shaft and a second following it closely carried them up into the dawn, Aang flailing his arms for balance after his last-minute spring to join them.

The ice was bloodied with the red and black uniforms of Fire Nations soldiers, held back only by a small group in blue and white: Yugoda and her warriors. The beginnings of a great ripple in the ice divided the two forces – could this have been the work of Yue and the gravity engines? Sokka knew it only took seconds for signals to travel to the Moon and back – but it was incomplete and the largest mass of the Fire Nations army was already poised to go around.

The rising sun glinted off a flame-shaped crown in the dark hair of the Fire Princess, her hand raised to signal the beginning of the onslaught.

Sokka saw the numbers, calculated the probabilities, and could come to only one conclusion.

"It’s over," he said, the words thick on his tongue and leaving behind an ashen feeling.

Because even if Yue survived, even if the correlator could be repaired, even if Zuko hadn't led his sister and her army straight to them – the was no way to prevent slaughter and destruction.

"No," came Aang's voice from beside Sokka, but it was changed. "It’s not over!"

Sokka looked, and Aang's tattoos were glowing in warning. Then Aang’s eyes lit up, and for the first time in over two hundred years, the world bore witness to the power of an Avatar.

Unlimited cosmic power looked very different in reality than in theory, Sokka noted in a daze. He could quantify it as much as he liked, but he would never in a million years have visualized it as the hidden waters of the frozen sea wrapping around Aang like a second skin, growing him taller and taller yet not even beginning to contain his brightness, the same way the tattoos could barely keep all that power together in one vessel.

The giant water-creature was silent as it advanced haltingly towards the front.

Azula’s arm swept down, and the red flood rushed to meet it.

“Toph, we need a wall!” Sokka yelled over the sudden roar of the opposing army. Aang, or the thing that had Aang inside of it, had tenuous control of its movements at best, and was heading straight for the Fire Nations army on a path that would take it dangerously close to Yugoda’s troops.

“I can’t see!” shouted Toph, but Sokka was already dragging her over to what he was ninety-nine percent certain had once been a rocket launchpad and digging through the snow to give her firm footing below. 

"We've got to... stop Aang... from going straight through... Yugoda's people," Sokka panted as he tore at the ice and snow. His fingernails scraped on concrete and he practically shoved Toph's foot into the hole, calling out distances and radius.

"Got it," Toph acknowledged, voice firm, and the concrete warped, moved, and nudged the water-colossus almost gently off to the side, where it continued its lumber towards the red-clad armies.

Sokka didn't spare an instant for a sigh of relief, because although the glowing waters surrounding Aang were absorbing the attacks of the Fire Nations soldiers, he could see the Fire Princess advancing at the head of a small group of doubtless elite soldiers. Blinding streaks of blue-white flame burst from her hands, cutting through icy missiles from the Baikonur defenders like… well, a plasma torch.

“That doesn’t even count as fire, that’s the fourth fucking state of matter!” Sokka screamed in frustration at the unfairness of the world. “God dammit!”

Something flashed over his head then and he ducked, his tug at Toph’s sleeve enough warning for her to pull up a protective concrete shell around them. Then an explosion behind them set Sokka’s ears ringing and the ground trembling. He didn’t have to look to know that most of the radio dish was gone now.

“Shit!” he yelled, but he didn’t even hear his own voice. This wasn’t how it was supposed to go; Aang had to know that, too, didn’t he? If it was even Aang inside that monster anymore, or if his peace-loving philosophy had finally given way to twelve-year-old fear and human survival instincts.

Across the battlefield, Sokka saw lightning sparkle from Azula’s fingers – which, okay, technically also plasma, so she wasn’t breaking physics there but still, holy shit – and knew he wasn’t the only person pissed off at Aang’s rampage.

“What the…”

Sokka’s hearing returned with a raspy voice behind him, and he turned as Toph lowered her protective shell.

“Fucking finally, you glorified flamethrower –”

“Toph.” Sokka cut her off; she couldn’t see Zuko’s face.

It was staring wide-eyed at the water creature, tossing Fire Nations soldiers left and right like toys, the sparkle in the cybernetic blue eye a subtle indication of rapid magnifications as Zuko inspected the battlefield.

“Zuko…” Sokka started, but for once he didn’t know what to say.

Zuko’s bloodied hand loosened on the battered and gory helmet he was carrying – Zhao’s, Sokka noted, and was ninety percent sure that by the way Zuko was holding it, it did not in fact contain a severed head inside it, although he was also one hundred percent sure that Zhao no longer had a head – and it clattered to the ground.

Zuko looked at Sokka, and at the same moment, the water creature twisted to look behind it. Sokka saw the moment Zuko recognized the arrow on its forehead, and knew what they had been hiding from him.

“That’s… that’s the Avatar.” Zuko sounded choked. “Avatar _Aang_.”

“Listen, buddy, I can explain _everything_ ,” Sokka promised hastily. “It’s not what it looks like—”

“It looks like the Avatar is killing my people.” Fire was back in Zuko’s voice. “It looks like Azula was right, yet again. So tell me why should I listen to you, when you never had enough honor to tell me this to my face.”

Sokka ignored the flare of pain through his chest and shouted back, fists clenched. “I don’t want this! Aang doesn’t want this, do you even know us? We…”

“ _Sokka_ ,” Toph clutched at his arm, sounding strained. “He’s coming this way!”

Sokka whirled to look, and indeed, Aang was on the retreat from Azula. A watery limb dipped to the ice to steady a stumble, and washed two of Yugoda’s warriors off their feet, before lurching to the other side and sending a Fire Nations attack vehicle crashing into the ice. 

Sokka heard the scrape of metal-on-metal, and glanced back at Zuko.

“Zuko…” He hated the pathetic pleading that seeped into his voice, but Zuko didn’t even spare Sokka a glance as he dashed off towards the fight, bare swords in hand.

“Fuck,” Sokka swore. “Toph, let’s go!”

It would all be all right, if he could only explain. Zuko had to understand that Azula was just manipulating him, that she was the type to willingly throw away the lives of her people in the quest for power, the same way she’d thrown away Zhao. And Aang didn’t mean all this destruction, surely; Zuko would see that, he knew the kid…

They didn't have far to run.

Aang was caught now in the divide Yue had started to build, growing impossibly larger as the Fire Nations kept assaulting him despite heavy losses.

“Sokka! Toph!” Sokka spared a glance backwards for his sister’s voice, relieved to see her gliding quickly up to them, Yue’s arm slung over her shoulder, their heads close together. “What’s going on?”

Katara looked exhausted, but resolute; one of her hair loopies was white, and in turn a streak of dark hair flowed from Yue’s bro. Starlight pinpricks of fibers still merged over most of one half of her body, but at least the princess was breathing despite the blood drenching the front of her clothing.

“Fucking _idiots_ can’t fucking _communicate_ –”

Sokka spoke over Toph’s shouts. “Aang’s inside that monster, we’ve got to stop him! And Azula! Well, actually, Zuko’s going to…”

Zuko was facing Azula now, both siblings on either side of the towering Aang, and Sokka saw the moment they locked eyes. His heart skipped a beat in anticipation; this was the moment, Zuko had _promised_ , it wasn’t goodbye, he had to come with them…

A sheet of flame unfurled from Zuko’s swords, collided with its target in a hiss of steam, and the water creature swayed back.

“No,” whispered Sokka, disbelieving, not even hearing Katara’s frantic questions or Toph’s angry swearing.

“Very good, brother dearest.” Plasma cut through the steam, revealing the Fire Princess giving a sarcastic mock-clap. “I knew you’d make the right decision, _the honorable choice_ , for our great Nations.”

Zuko’s tone was broken as he replied, and Sokka dared to hope. “Azula, I…”

The water beast roared, only the voice was Aang’s; ice followed Katara’s instinctive command, solidifying beneath him while cracking open the glacier to form a chasm separating enemies and friends.

Across the divide, Zuko turned back towards them.

Two blazing golden eyes met Sokka's. Sokka felt his stomach plummet, and he wasn't even falling.

He saw Zuko's lips part, as if to say something. High above them all, Aang’s borrowed watery form loomed, thick limbs rearing back. On the ground, Azula matched his stance in challenge, two fingers pressed tightly together in a pointed threat.

Caught out of time, Sokka strained to hear. He didn’t know what he was expecting; a battle cry, a warning, an apology, or even a farewell, just that he was hoping for something, anything, an acknowledgement of who they were, or what they could have been.

It never came. Zuko's mouth hardened into a stern line, and he turned away.

Lightning flashed, and then the Avatar was falling, falling, falling.

Aang landed limp in Katara's arms.

No one caught Sokka.

**Notes for the Chapter:**

> Ehhhh, so how we doing there, y'all? *runs and hides*
> 
> Well you know me, I'll never ever write Crossroads of Destiny different than canon, unless there's some other way that Zuko manages to get everything he ever wanted (or thought he wanted) so he can realize that it wasn't worth it (spoiler: I have never once seen this done properly in fanfic, so canon outcome it is). Hey, there's Yutara though! That's sweet, right? And I know I didn't have the right narrative setup to describe the Katara-heals-Yue scene, but in my head it looks like that Tui and La gif where the fishes are circling each other and blurring together into the yin/yang symbol… only it's the swirl of their hair surrounding each other, with Katara's new white streak and Yue's brown streak, and they're gazing into each other's eyes and there might be some ambient sparkles from the fiber optics still stuck to Yue. P.S., very willing to pay an artist to depict this, please get in contact if you're interested.
> 
> Anyway, special thanks to Yue for doing a Princess Buttercup leap into the oasis, that really got this whole finale back on track after being stuck for a while.
> 
> I don't know when the next arc will be ready, but it will probably be two or three months due to life being hectic at the moment. I will be some posting some One Punch Man and BnHA utter stupidity in the next few weeks though!
> 
> [Works Cited, part 2](https://d-naggeluide.tumblr.com/post/630245207229792256/dancer-a-disclaimer-and-works-cited)

**Works inspired by this one:**

  * [Gravity](https://archiveofourown.org/works/27267100) by [naggeluide](https://archiveofourown.org/users/naggeluide/pseuds/naggeluide)




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